Growing Hydroponic Lettuce | Caleb Johnson | Skillshare

Playback Speed

  • 0.5x
  • 1x (Normal)
  • 1.25x
  • 1.5x
  • 2x

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Watch this class and thousands more

Get unlimited access to every class
Taught by industry leaders & working professionals
Topics include illustration, design, photography, and more

Lessons in This Class

    • 1.

      0 Introduction


    • 2.

      1 Basic Needs


    • 3.

      2 Hydroponic Systems


    • 4.

      3 Water


    • 5.

      4 Nutrients


    • 6.

      5 Air


    • 7.

      6 Light


    • 8.

      7 Environment


    • 9.

      8 pH


    • 10.

      9 Varieties


    • 11.

      10 Planting


    • 12.

      11 Harvesting


    • 13.

      12 Troubleshooting: Bitter Lettuce and Bolting


    • 14.

      13 Troubleshooting: Tipburn


    • 15.

      14 Troubleshooting: Plants Stretching


    • 16.

      15 Troubleshooting: Slow Growth


    • 17.

      16 Troubleshooting: Leaf Curl


    • 18.

      17 Troubleshooting: Root Rot


    • 19.

      18 Troubleshooting: Pests


    • 20.

      19 Demo: Nutrient Change


  • --
  • Beginner level
  • Intermediate level
  • Advanced level
  • All levels

Community Generated

The level is determined by a majority opinion of students who have reviewed this class. The teacher's recommendation is shown until at least 5 student responses are collected.





About This Class

Tired of lettuce recalls, stale lettuce, expensive lettuce, hard-to-grow lettuce? Consider hydroponics! Hydroponics is a great way to grow lettuce simply and efficiently. Lettuce grows really well with hydroponics since it allows you to more easily control factors such as temperature, pests, water and nutrients and allows for steady, year-round production. Give hydroponics a try!

In this course, we take the guesswork out of growing hydroponic lettuce in your home or greenhouse! We'll go through how to meet all of the growing needs of lettuce hydroponically. We'll cover the specifics of nutrients, lighting, pH, and how to manage these things in a simple and effective way. We'll share our favorite lettuce varieties that work best in hydroponic growing settings, and give a thorough troubleshooting guide for dealing with common problems gardeners may face in their hydroponics journey such as tipburn, bolting, root rot, pests, and more. We are all about simple, and we desire to make growing hydroponic lettuce something that is attainable for you!

Note: This course does not go into detail on how to build and set up a hydroponic system - for a detailed guide on building a hydroponic system, check out our other course "Build Your Own Home Hydroponic Farm".

We've created a web page with a list of materials you may need when growing lettuce. See it here:

Meet Your Teacher

Teacher Profile Image

Caleb Johnson

Simple Greens Hydroponics


Hello! I enjoy growing hydroponic produce as simply as possible and teaching others to do the same. We've spent several years (and lots of prototypes) designing a system that is easy to maintain and super productive. I'd love to help you set up a system and grow food right in your home!

See full profile

Level: All Levels

Class Ratings

Expectations Met?
  • 0%
  • Yes
  • 0%
  • Somewhat
  • 0%
  • Not really
  • 0%

Why Join Skillshare?

Take award-winning Skillshare Original Classes

Each class has short lessons, hands-on projects

Your membership supports Skillshare teachers

Learn From Anywhere

Take classes on the go with the Skillshare app. Stream or download to watch on the plane, the subway, or wherever you learn best.


1. 0 Introduction: Let us can be some of the most frustrating produce to buy in the store. It is often recall for bacterial outbreaks, it can be expensive, it can be better, and often goes bad within a few days. Let us can also be a challenge to grow. And most climates, as it doesn't tolerate heat and can't be grown outdoors at all during winter in colder climates. Thankfully, lead us is fairly simple to grow hydroponic li, it can be grown indoors year round in a small space and requires very little water and nutrients in order to grow. And best of all, the end product, it's fresh and delicious. In this course, we go through the basics of growing hydroponic lettuce. We'll focus on what needs let us has and how we can meet those needs with hydroponics in a simple way. We've also included troubleshooting for problems you may encounter when growing lettuce and how to solve them. This course, we'll only briefly touch on various types of hydroponic systems for a guide on how to build and set up a hydroponic system, cr, other course on building a home hydroponic rail system. Whether you've just started with hydroponics or have some experience. We believe this course will give you the knowledge and tools to grow delicious hydroponic lettuce. 2. 1 Basic Needs: Let us has a few basic needs and ask growers if we meet those needs, we can successfully grow lettuce. With hydroponics, sometimes it can feel like we are growing a completely different plant or trying to meet different needs. But it's all the same needs. The plant has been groaning dirt. We are just meeting those needs in a slightly different way. So what are the needs? Let us needs water. Like most plants, let us need water to grow and perform basic functions within the plant. Fortunately, with hydroponics, this is usually the simplest need to meet. Next, let us needs nutrients in order to grow and mature. Let us needs access to nutrients and needs the ability to pull those nutrients from the water or soil. We'll go over a simple nutrients schedule and factors that influenced the plant's ability to intake nutrients. Let us also needs air, specifically oxygen and carbon dioxide. Both are essential for basic functions of the plant. The roots also need oxygen, which sometimes conflicts with the need for water, which we'll talk about. Let us needs light. Light provides the energy needed for photosynthesis. Light can come from the sun or man-made light sources such as grow lights. And finally, lettuce needs the correct environment. The environment includes factors such as the temperature, humidity, airflow, pests, and pH. It may sound complex, but many of these are simple to meet with hydroponics. In this course, we will look more in detail at how we can meet each of these needs with hydroponics and grow healthy, delicious lattice. 3. 2 Hydroponic Systems: Next I'll briefly go over a couple of different kinds of hydroponic systems that you may come across. The first type of system we'll look at is one that uses the crack key method. So at the cracking method, a plant is suspended over a container of nutrient solution. So as time goes on, the plant law slowly absorbed the water and nutrients that are in the container. And the roots of the plant won't grow down farther and farther. So then the plant gets its oxygen from this airspace between the top of the container and the top of the water level. So this section of roots will pull in oxygen. And then down below are the roots that are in the nutrient solution will be pulling up the nutrients. So the nice thing about this type of system is that it's really simple. Requires no electricity, no pumps, no air raiders, nothing like that. The disadvantage is that you can have slower growth with this system. And there are some plants that don't like to grow in this type of environment. Another type of hydroponic system is called the deep water culture or PWC. So PwC is pretty similar to crack key where you have Plants suspended over a container of nutrient solution. However, this time there's an air raid or in the bottom of the container, and that's what provides the oxygen to the roots. So with the deep water culture, you have to maintain the water level where it is. So that requires frequent water changes or adding water to top off the nutrient container. And then the narrator, which requires electricity, then keeps the oxygen near the roots. Another type of system is it drip system. So with a drip system, you have the plant in a container. But this time you have a growing medium in there as well. So this could be hydrogen or pearlite, just something to give the root something to grab onto. But then water is pumped up from a reservoir container and then it slowly dripped onto the plan. So the plan is still getting its nutrients from the water that's being dripped onto it. But it's not completely submerged in water like like crack key or PwC. And this type of system is really good for really big plants because it allows the big plants too send their roots way down into the growing medium and really get stable. So something like tomatoes and peppers, this can be really good. Another common type of hydroponic system is a nutrient film techniques system or NFT. So with NFT system, you have your plants spread along a gutter or a rail, and that rail is then put in a slight decline. You then have a reservoir that has nutrient solution in it and a pump. The pump pushes water up from the reservoir into one end of the rail. Then that water flows down the rail and then exits back into the reservoir. Along the way down the rail. It's kind of the, the film of water. That's where the name comes from, is nutrient film of water contacts the roots of the plants and the plants get their nourishment in water from this film. So this is really good for smaller plants like lettuce that grow really fast, that you harvest pretty often. It's not very good for tall plants like tomatoes or peppers, because there's not really much for the plant roots to grab onto and so they would took over. But this system allows you to grow a lot of different plans with a relatively small reservoir. This rail could be really long and then the exit tube could come all the way back and come back into this reservoir. So this can really expand how many plants you can grow with a given amount of a nutrient. The final type of system we'll talk about as a flood and drain system. So you'll see there are some similarities to an NFT like we just talked about. So you'll have your plants spread out along either a rail or this could be a tote or some other container. And then you have a larger reservoir underneath it. And again, there's a pump and a reservoir that pumps water up into your container with the plants. However, what it does is it fills up the reservoir, fills up the container until it reached reaches this outflow height. Once it reaches the outflow height, the water starts to exit through this outflow pipe back into reservoir. So it maintains the water level here for a little bit. And then when it turns off and the pump turns off, the water drops back down to where the inlet is. So you end up with a water-level that goes up and down throughout the day. So this when the water goes up, it waters the roots and gives them nutrients. And when it comes back down that allows the roots to get oxygen. So we just took a brief look at these five different types of systems, but there's a lot of different kinds of hydroponic systems and there's new types being developed all the time. And there's actually quite a few systems that are hybrids of some of these five. The system we like to use, which you'll see reference throughout the course, is actually a hybrid between NFT and PWC. But any of these options can work for lettuce. 4. 3 Water: The first need we'll look into in depth is water. Water is very important for plant growth and much of the full grown lettuce head will consist of water. With traditional and gardening watering can be one of the more difficult needs to meet and to monitor. Thankfully with hydroponics water is probably the easiest need to meet. One of the major advantages of hydroponics is that it uses so little water since the water is contained within the system and then recycled. There are a few considerations, however, the main thing you'll want to consider is your water source. The ideal water supply for growing hydroponic lettuce would have no chlorine, no dissolved solids, a neutral pH, and it would be free of algae or other organisms. I'll go over each factor and then talk about possible water sources. First, chlorine. Chlorine can be damaging to the roots of lettuce. Chlorine is often added to municipal water supplies to kill pathogens, but it should be removed or avoid it as best as possible. When you are preparing water to add to your hydroponic system. Dissolved solids. Dissolved solids include any salts, are minerals that are already present in the water. When we add nutrients to the water, we will be adding dissolved solids. However, if the water already has dissolved solids, then we don't know what nutrients or minerals could already be in the water. And this can make adding nutrients a little more challenging. Thankfully, let us pretty resilient to nutrient variance. So for most cases this isn't a huge issue, but still something to consider. Next, an ideal water source would have a neutral pH. We'll talk more about pH in a later video. But as a summary, lead us girls best with the pH around six. If we start with water at a neutral pH of seven, the pH will naturally move court 6 once nutrients are added without any additional changes. So that makes things simple when preparing the water. And lastly, we want the water to be free of algae or other organisms. We want to be careful that the water we use doesn't introduce pests into our system. Algae, bugs or other organisms can have a negative impact on your hydroponic lettuce. So clean water is best. So given these factors, the best water source that I've found is rainwater. Rainwater has no chlorine near 0 dissolved solids, a neutral pH, and no algae. If you have a rain barrel or other method of catching rain, this can be a great source of water. However, be cautious of using rainwater that's been sitting out in the sun are stored in a dirty container. Because that provides an opportunity for other organisms, algae or bugs or other things to get into the water. Another near ideal option is a reverse osmosis water if you have access to it. Similar to rainwater. Ro water has no chlorine, no dissolved solids, a neutral pH, and no algae. However, it can be really expensive to install a system if you don't already have one. And in most cases, it's not necessary. But if you happen to have access to one, that's a really good option. Though not as ideal. Regular tap water can still be a great option and is what I use most of the time for city water supplies. It often contains chlorine, dissolved solids and may not have a neutral pH. However, chlorine can be removed fairly easily. The simplest method I've found is to add a query and water conditioner, or ascorbic acid, which is vitamin C to the water before pouring it into the system. Fill up a bucket with tap water at the water conditioner or vitamin C, and then wait several minutes for it to neutralize the chlorine. The dissolved solids are a factor to consider when adding nutrients, which we'll talk about later on. But it's often not a big issue for lettuce. Ph can also be adjusted as necessary, which we will talk about later on as well. Water from a well should work fine also in may not have some of the issues that city water has. Depending on the source and location, I would be cautious about pulling water out of a marsh pond or lake. Though. If that was your only option, then it may still work. Considering your water source can be really helpful. But if it seems overwhelming or if you only have access to one source, then just go with it and don't get concerned. You can easily make adjustments later on if you run into any issues. One more note about water. It's fairly straightforward when doing hydroponics, but I should mention it. You want to make sure that your system allows for the roots of the plants to contact the water in some way. So whether that be immersed in the water, having water flowing over the roots, having water sprayed on the roots, the roots need access to water. What's also important is that the water needs to have oxygen in it. Are the roots neat, at least have access to oxygen? So we'll talk more about that in the air section as one of the five needs of lettuce. But I wanted to include that note in the water portion here. 5. 4 Nutrients: Nutrients are very important for growing hydroponic lettuce. And they can seem very intimidating, especially if you're just starting out. The good news is with a routine and an understanding of what's going on in your system. It's something you can easily manage. Like most plants, let us needs a wide variety of nutrients in order to grow. Thankfully, there's nutrient mixes available to meet these needs that have all of the major nutrients and micro nutrients that the plant needs. Let us as a mild feeder. So it doesn't take as much nutrients as some other plants might. And it's also tolerant of a wide range of nutrient levels. So that makes it a really nice plant to grow, especially when you're just starting out or if you want something that's simple to manage. Let us also doesn't flower, at least that's not the goal. So the nutrient requirements remain relatively stable throughout the growth cycle. Plants that flower have a different nutrient requirement once they're producing fruit than when they're just growing leaves. But we don't have to worry about that with lettuce. There are a couple of factors when choosing a nutrient mix. The first one is whether you choose a mixin nutrient or a premixed one. So mixin nutrients are usually a dry powder or material that you put into the water and then mix it in until it dissolves. Whereas a premixed nutrient will come already mixed in concentrated in a solution. And then you put some of that solution into your nutrient reservoir. And that makes your nutrient solution. So the mix in nutrients sometimes take a little bit more work, or sometimes they have multiple parts where you mix one in wait till it dissolves, mix and other one we till that dissolves. Whereas the premixed can be fairly simple. You just put in a specified amount and you're done. However, the dry nutrients are almost always cheaper because you're not paying for the water that's being shipped to you in the premixed liquid. Another thing to look at when choosing a nutrient mix is the NPK number. So a lot of times when you're buying a nutrient or a fertilizer, you'll see three numbers on the bag. And that's the NPK, nitrogen, phosphorus, and potassium. With NPK, the ratio matters more than how high each number is. If there's a nutrient that has really high numbers for all three, that just means that that nutrient is really concentrated. If you have a 10, 10, 10, and a 20, 2022 different nutrients, the 23rd 2020 is just twice as concentrated as the 10, 10, 10. Both of them have the same ratio. So the ratio of those three numbers is what you want to look at when you're picking a nutrient mix. We've used nutrients with a ratio of one to one to two and two to one to three. And both worked really well. Let us doesn't need as much phosphorus since it's not fruiting. So generally, the first number, the nitrogen, and the third number, the potassium, will be a little bit higher. Then the middle number phosphorus. When you're picking out a nutrient solution for lettuce. There's quite a few different commercially available nutrient mixes. And if you pick one that's made for vegetative growth, you'll see options that are geared towards vegetative growth that will work well for lettuce. Once you've picked your nutrient mix, then you have to think about what is the nutrient concentration you want to shoot for. So nutrient concentration is measured in ppm parts per million, or in electrical conductivity. Ec. Nutrient concentration can be measured pretty easily with a simple tool. You just take the tool, dip it into your nutrient solution, give it a gentle shake and it will tell you what the PPM or electrical conductivity of your nutrient solution is. That measured value will include other dissolved solids that are already present in the water. So if you get your water from the municipal water supply, they often add things beforehand to treat the water. So you may already have a 150 to 200 ppm just when your water comes in the tap. And then that measured value will include both the pre-existing. Ppm along with the nutrients that you added. So it's really measuring the concentration of all dissolved solids in all nutrient solution. There are methods to individually measure each type of nutrient. So you could get a measurement of how much nitrogen or phosphorus is in the water. But the tool to do that are really expensive. Often you have to send it to a lab to have that done. So it's not something that's practical for most people for home hydroponics. As a result, when we take measurements, we don't know the exact concentration of all the different nutrients. Instead, we're just getting a snapshot. Overall how many dissolved solids are in the nutrient solution. However, knowing what nutrient mix you're using, you're going to have a pretty good idea of what's in there at least to begin with. And those nutrient levels will change as time goes on in the plants use up various nutrients. But that's why it's important to reset the system and drain out the water every few weeks and then replace it, which we'll talk about in a minute. Let us as flexible on nutrient concentration with a level between seven hundred and one hundred, ten hundred ppm being ideal for lettuce. When targeting and nutrient concentration, you want to factor in the dissolved solids that are already present in the water source, like we mentioned a minute ago. So if you're a water starting out with 200 ppm, you may want to go up to eight or 900 ppm with your final nutrient concentration. Factoring in that 200 of those PPM are not necessarily nutrients. However, sometimes the pre-existing dissolved solids that come from a city water supply or something like that, may be usable by plants. Sometimes it's calcium or magnesium that are in the water. So some of that, some of those dissolved solids could still factor into the number. Thankfully, lettuces good with a wide range. So it's not a big deal unless you're starting out with water that's really high in dissolved solids. So just consider what you're starting with when you are mixing up your nutrients. Once your hydroponic system is up and running, making a nutrient routine can take the guesswork out and make things a lot simpler. When you have a routine. And you know, kind of the pattern of what your system and what the nutrient concentrations do, then you won't need to do constant monitoring of the nutrient. You won't be checking it multiple times a day or something like that. I've had it where I can go five or six days even up to a week. And I don't have to constantly check it because I have a good idea of what's going on. Let's go through an example of routine of what this might look like over the course of a two-week period. The actual timeline of this could be different for you depending on what type of system you have and how big your reservoir is, and how many plants you're growing, things like that. But the general idea should be transferable. So on day one will fill up our reservoir, will add nutrients until the concentration of 7800 ppm is met. And depending on what nutrient mix you have, they'll often have it either on a website or on the bag of how much to add, how many nutrients to add for each gallon of water and your nutrient solution. And that, that will get you close. Again when you've done it a lot, you'll have a good idea of, you know, if I have five gallons of water and I add one tablespoon and nutrients, that'll get me pretty close to 700 ppm or something like that. Then after a week on day eight, the water level will have dropped in the reservoir just from the plants using water and water evaporating out of the leaves or water evaporating out of the system directly. And as that happens, the nutrients will usually concentrate over time because of that evaporation. So even though the plants are using nutrients, since water is evaporating, there's less water. And so the end result is the nutrients actually concentrate a little bit over the course of that week. Generally, when I measure ppm after a week, it's around a 1000 ppm, maybe 1100 ppm. So then at that point, I'll add water back to the reservoir to get it to full. And then I'll add a half dose of nutrients. To get it back up to the seven to 800 ppm. If you add in the full amount of nutrients for the new water, you'll probably end up with concentration that's a little higher than what you need. Then after another week, day 15, I will drain and fill the system. So at this point, the plants have been in the nutrient solution for two weeks. We don't know exactly what nutrients they've pulled out and which ones are left. And over that time there can be certain salts or things that will accumulate, especially if you're using city water as you keep adding water. Some of those salts are minerals won't be used and so they are just gradually accumulating. So it's a good idea after two weeks to drain out the water that's in the system and then put in some fresh water and fresh nutrients. To make this easy, what I do is I have a pump similar to the pump that circulates water through my system and it's attached to a half-inch tubing. And so I can put that submersible pump into the reservoir that I'm looking to drain. And then I can put the other end of the tube either into a bucket or in a sink if I'm close enough. And then I can go ahead and pump out all the water out of that. Whereas for and usually I'm not too picky. I'm not trying to get every last drop out of the reservoir. I'm just getting the majority of the water out of the reservoir and then replacing it. Every once in awhile if stuff is building up on the bottom of your reservoir, you can take You can drain out most of the water, take out the entire reservoir, and then dump it and start fresh. But you don't need to do that every time. Then we can start the cycle over. We'll add water to the reservoir, then add nutrients to get the concentration to seven hundred, eight hundred ppm. And then the rest of the steps are all the same. Again. Like I mentioned, the exact number of days that I give here, the two-week cycle. It's not necessarily what you need to do. You might be able to go longer, especially if you have a large reservoir and you don't have very many plants. But this could be a good starting point that you could use. One way to tell if your cycles going too long is if, say, at Day 8, your nutrient concentration is up at 1300 ppm or 1400 ppm. Then you know that the water's being used up really fast. And so you may want to shorten the time. However, if at Day 8, you're only at eight or 900 ppm, well, that might say, Hey, you can go on another couple days before you have to do a top off. And then you can extend your drain and fill a little longer to when you have a routine like this. It really makes managing nutrients and managing your hydroponic system a lot simpler. 6. 5 Air: Air is a plant need that is often overlooked, but very necessary. Air is not a scientific word, of course. Really, we're talking primarily about oxygen and carbon dioxide. For hydroponics, the primary consideration is actually getting oxygen to the roots of the plant. Similar to the effect of over watering a plant. Dirt path. If there's no oxygen present near the roots of our lettuce, then it will be suffocated and experience stunted growth. There are two ways to get oxygen to the roots. Either exposed them directly to the air without letting them dry out, or add oxygen to the nutrient solution. The crappy method relies on air contacting the root for oxygenation. This is why it's important not to keep the growing container full of water as the plant grows. You need some airspace in there so that the air can contact the roots and provide oxygen. An air pump with a bubble stone or a bubble bar is a simple way to add oxygen to the nutrient solution. Water that's flowing or falling through a system can also add oxygen to the water. A deep water culture system relies on an air pump to provide oxygen for the plant. The rail system I like to use utilizes both methods, where the water is oxygenated by an air pump and by waterflow. But the low water level and some of the rails allows for the air to directly contact the roots, similar to the crack key method. So you have oxygen in the water and you have some extra space in there for air to directly contact the roots. The leaves of the plant also need air contact, but this doesn't require much special consideration unless you're growing in outer space or something like that. However, for lead us in particular, it's been shown that higher levels of carbon dioxide around the plant result in higher yields. A simple way to achieve this is by using a small fan to circulate air near the plants. This moves oxygen off the surface of the leaves as it's generated by the plants and allows them greater access to carbon dioxide. For the photosynthesis process, it's definitely not necessary, but something to consider if you really want to dial in your system. Fan can also help with managing heat and humidity, which we'll talk about later on. 7. 6 Light: In this session, we'll talk about lighting. The first question to ask is, what is your light source going to be? Sunlight can be a great option because it requires no setup and no electricity. Just put your plants in the sun and they'll grow. However, the disadvantage of sunlight is you may not have access to it depending on where you live. If you're trying to grow indoors, can be difficult to get access to sunlight, and then temperature control can be difficult. So in the summer, it can really increase the temperature of your plants. And with lettuce in particular, we don't want the temperature to creep too high. Also, if you're in a northern climate, the sunlight usually isn't strong enough in the winter to successfully grow lettuce. Artificial lighting is nice because it can be used anywhere. You can use it indoors. You can use it throughout the seasons. It doesn't matter if it's winter or summer, doesn't matter if it's cloudy outside or what the weather's doing outside. But of course the trade-off is you have to pay to buy into R1 it, pay for the electricity to run it. And also it require some setup to fit it up above your system and get everything in place. If you do choose to go with sunlight, you can probably end the video here. The rest of the time I'll be talking about how to pick an artificial light and what the factors are to consider. There are several different types of artificial lighting you can get. The first one is fluorescent lighting. Fluorescence are fairly cheap to buy upfront and they're pretty easy to find. A lot of people may even have them laying around in a shop or something like that. The disadvantage of fluorescence is they require more electricity and they generate some heat. Led grow lights are more of a recent development. And there's been quite a bit of progress made on using them as grow lights for hydroponics. So the advantage of LED is that they use a lot less electricity. So that results in a lower costs to run and less heat output. In my experience, they use about half the electricity that are fluorescent bulb would use for an equivalent amount of light. The disadvantage of LED is that they generally have a higher initial costs. Though the prices keep on coming down. So it's not that big of a difference at this point. Another advantage of LED is that there's a lot of different spectrums and types and sizes you can get to fit the space that you have. So you can really customize to fit the situation that you're growing in. Let's talk about light spectrum. So plants utilize certain wavelengths of light more than others. This diagram here shows the visible light spectrum. And plants tend to use light from this blue section in this red section for photosynthesis. Whereas our eyes tend to more easily see light from the green and yellow section. However, since LED lighting is fairly new technology and the ability to really control which spectrums are produced by grow lights is so new. There's quite a bit of research ongoing about which spectrums work well for plants and which ones they use and which ones are optimal for growth. And there is some evidence showing that plants do need some light in this yellow and green section. When you look at grow lights, they usually have a diagram that looks like this, showing the spectrum of light that is produced by the girl light. And they'll all look a little bit different, but usually they have a peak in this blue section and the peak in the red section. Sometimes there's less green and yellow, especially if it's 0. Purple light. I've tried quite a few spectrums, and I haven't noticed a huge difference when growing lettuce between the different spectrums. One thing to note is the screening yellow light. Even if it's not needed as much by the plants, having some green and yellow can be helpful because then it makes the light appear to us more white. So then if you're working near the lettuce or near your system, you won't have the purple light making everything purple around you. And it can also make looking at the lettuce easier. So you can more easily tell if you have a problem because the colors will look more like what we're used to seeing as opposed to underneath the purple light. But when you're looking for a light. Generally, if there's a peak in this blue section and in the red section, then it'll probably work. Well, here's one setup I've done where I've got two rails growing lettuce here. And above 52 LED light strips that are attached to the level above just with a zip tie. And so this is a really simple setup, really easy to do, and then you can stack them vertically. So I have another system up above this one. Here's an example where I set up a system underneath my stairs. And so there's not a nice flat surface to hang from above. In this case, I decided to use a single light fixture. That way There's just two hanging points that I have to worry about. Instead of having multiple light strips that each half to be hung from the ceiling above. So if you have a space where you're hanging from the ceiling or an uneven surface. Having a single fixture can do really well. And you can see here, this fixture provides nice uniform light over the curling area. One other thing to note, having reflective material on the sides around your system can really help to increase the light around the edges in the corners. As adults tend to have less light than in the center. So that's something that can help make your lighting even more uniform, putting reflective material around the edges. The intensity of your lighting is also really important. Intensity of light for plant is measured differently than the way we measure it for what the human eye can see. So there's a couple of terms that you may see if you have done some reading on this. So the first one is par, and this is light in the spectrum of 400 to 700 nanometers wavelength. And this is the light that's generally considered usable for plants. They can use some light outside of this spectrum, but this is the, the spectrum of light that plants can use. And so we're not, we're not including light that's outside of that spectrum. There's also a PFD. And this is similar, but this is a measurement of the amount of light that's hitting a surface that a plant can use. So it's measuring the amount of light within the par range that the plant can use. One thing to note here, P PFD is different than a measurement like lumens that measures the brightness of a light for the human eye. That's because the human eye senses light differently than plants do. And so you can't necessarily compare brightness between two lights just by looking at it or by using lumen values. Because those are looking, are measuring brightness in a different way than PPF D does. Lead us doesn't require a whole lot of light. And it's fairly flexible on how much light it can take. The ideal value for PBFT is somewhere between 250 and 350. If you're less than that, it can result in a little bit slower growth. And your plants may start to look stretched out. And if you go more than that, you can start to get tipped burn or things like that where the plants just growing too fast to keep up with itself. So anywhere between two hundred and fifty and three hundred and fifty is usually a good range to determine the PPF d of your lighting. It's actually fairly difficult because you need complex measuring device, which can be really expensive. However, thankfully, grow lights usually show a chart of PFD readings at various heights and then distance from the center under the light. So if you look at the materials that come along with a grow light or on that advertising page, you'll often see chart or a diagram that shows the PPF d values and that will generally be higher PBFT values the closer you are to the light. So you want to look at what are the readings at the distance you are going to use. So if you're like us, we usually have our plants 15 to 18 inches below our lights. So you could look at what does the chart say the PPF d value is at, say, 18 inches under the light. Another thing with PFD is that it's cumulative from all the lights that you're using. So if you're putting two LED light strips next to each other in each one provides a 100 PPF D to a 0.18 inches under the light. But you have two of them next to each other. You can add those together. So the combined effect of the two lights will be 200. It's also important to keep the lighting is uniform as possible over the surface of your system. Generally, this is the hardest on the edges. The middle will usually have the most light right beneath the center of the light that you're using. And then the corners and edges will have less. So having either several different lights that are spaced out across the area that you're trying to cover. Using a large fixture that covers the whole area can do well to keep your lighting uniform. As for duration, 14 hours of artificial lighting per day works well for lettuce. If the PPF D is less than the 250, running lights, longer for a longer period of time each day can help to make up for the lower light intensity. So then which light should you buy? Well, the first option is just to use something you already have. So if you already have some fluorescence or you already have a grow light you've used for starting seedlings in the past four, an outdoor garden. Go ahead and use that if you want to get started for cheap. The other option is to buy, grow light that fits your budget and fits the space that you're going to be growing your lettuce. My recommendation would be to buy an LED light. The long-term savings from having less electricity and less heat. More than makes up for the initial cost. For a vertically stacked system. You can buy LED light strips are tubes that are individual and they can easily be attached to this shelf above. Those are usually the cheapest option for LED. And they're really easy to set up that way. You're hanging from the ceiling or something a lot higher. I'd recommend buying an LED light panel or a fixture that has all the lights built into one panel. And choose a size that can cover the growing space that you're going to have. And finally, when choosing a light, make sure that you choose one that has a gross spectrum, that has some blue and some red, a little bit of green like we talked about. And also look to get one that will give you the right intensity of light. At the height that you plan to put the light. There can be a lot of complexity when you're looking at choosing a light. But if you just boil it down to those couple of rules, getting the right PFD and then getting a good growth spectrum. A lot of the other stuff. You can tweak it and try to get things a little bit better. But I've tried quite a few different lights and I don't notice a major difference between them, even with a little bit different spectrums or things like that. So if you don't want to dig into it too far, just pick a good grow light and put it at the right distance away to get a good P, PFD. And you should be good to go. If you'd like to see specific examples of grow lights that have worked well for us. Check out our website. We've got a list of different lights, as well as some information about how we set them up. 8. 7 Environment: The environment or your lettuce is growing is very important. Growing indoors gives us a much greater degree of control over the environment and is one of the main advantages of indoor hydroponic growing. It turns out that lettuce prefers a similar environment to people. So it can be easily grown in a home environment. We'll take a look at a few environmental factors to consider. The first is air temperature. Air temperature is very important and the hardest thing to deal with when growing lettuce outdoors. Let us does not like heat and it will bolt, send out flowers. When it experiences heat. Making the lattice bidder. It's probably one of the main reasons people don't like to grow lettuce or have had a bad experience growing lettuce. Some varieties of let us have been developed to resist bolting, which can increase the acceptable air temperature range. But we found it's good to keep the air temperature below 75 degrees Fahrenheit. On average, short periods near 80 degrees will often be okay if the temperature comes back down at night. Let us as not very sensitive to cold however, saw on cold winter days, we've had our grow room dropped to 50 degrees at night and the lettuce stilted, great. 60 to 75 degrees Fahrenheit seems to be ideal. The next thing to consider as water temperature. Water temperature is important, but sometimes overlooked. High water temperature or causes it dissolved oxygen to go down and increases the chance for root rot. Water temperature in the 60 to 70 degree range is ideal. If you're using a recirculating system with a reservoir, keeping the reservoir and a cool floor away from heat sources and out of the sun can help to keep the temperature down. For this reason, basements tend to be good, good location. Crack key or PwC systems can be trickier in this regard, since they're just one unit and the plant needs to be in the sunlight or under a crow light. So you can't really take the water away from the light source to try to keep the heat down. Using containers with opaque and reflective outer coating such as white paint could help in this situation. Low water temperature isn't as big of a deal, but it does slow down the growth. So if you're in a cold climate, you can use a submersible aquarium heater to keep the temperature up above 60 degrees Fahrenheit if you want to keep the growth rate up. But this is definitely not necessary. The lead us will still grow fine if the water's cooler and it'll just be at a slightly slower rate. Humidity is another factor, but we haven't found lead us to be very picky about humidity. Or humidity is usually between 40 and 60 percent relative humidity. High humidity can increase the chances of tip burn, which we'll have a separate troubleshooting video on that if you want to look more in detail at how that happens. But usually the humidity doesn't require precise monitoring or adjustment. If you're in a climate with really low humidity, you should still be fine because just having the system indoors should elevate the humidity a little bit. 9. 8 pH: One of the more seemingly complex parts of hydroponics is pH. It can be somewhat mysterious and invisible, but similar to nutrients that is relatively simple to manage. As long as you have a routine. Ph is the measure of acidity in the hydroponic nutrient solution. It affects the plant's ability to uptake nutrients from the water. So if the pH is too high or too low, then the plant won't be able to efficiently pull nutrients from the water, and that will stunt the growth. For lettuce, the ideal pH is between 5.56.5, which means that the water slightly acidic. So this statement may be controversial for some people, but if you wanna do hydroponics as simple and as cheaply as possible, you may be able to ignore pH altogether. We grew, led us successfully for several years without measuring pH at all. For many water supplies, simply adding nutrients will bring your pH close to the range let us likes. And so you can be blissfully unaware of what the pH is doing and still be growing really nice lettuce. So the pH still matters. But just the way that things tend to work out when you add nutrients to water. It usually brings it to a good range and so you don't have to worry about it. However, if you encounter issues or if you want to dial things in right away, actively managing pH can be helpful, and it's not hard to do. The first step towards managing pH is measuring the pH of your water source. To measure pH, I found the pH test kits with the drops to be the easiest to use in most cost-effective. To measure the pH of your water source. Fill up a bucket or container with water, and use your pH test kit to find the pH. As a reference. Rainwater is usually around 7 and the tap water I've used is usually between 7.57.8. After adding nutrients, pH will go down. But knowing the pH of your water source can help you predict changes in pH when you add water to your system later on. Next, you'll want to measure the pH after adding nutrients and allowing them to fully dissolve. In my experience, pH drops around 1 after adding nutrients. For many water sources, simply adding nutrients will bring your pH to the half range of 5.5 to 6.5. If this is the case, you're done, you're good. However, if your pH is near 6.5 or above, you can add acid to your nutrient solution and further drop the pH. Lemon juice can work as an asset to drop the pH. Otherwise, there are additives you can buy that are designed to bring the pH down in hydroponic systems. In my experience, pH never goes too low. But if you encounter that situation, there are also additives available to raise pH. As the plants use nutrients, the pH will slowly creep upwards. This is expected, and as long as you're doing regular water and nutrient changes, the pH should keep getting reset each time and stay within the ideal range. So that's all there is to it. Don't let ph be something that stops you from jumping in and trying hydroponics. 10. 9 Varieties: With hydroponics, you can grow just about any variety of lettuce that you'd like. But there are certain types that work better. We found that compact varieties work a lot better because they use the space more efficiently. You can grow big heads of Romaine or something similar. But the problem is the leaves really like to spread out and take up a lot of space. So especially when you're using an artificial light that can be a negative. There are other kinds of Romain that do grow tighter like this is an example. I think this variety is Monte Carlo. So it grows a lot tighter heads and doesn't spread out and take up space. Our favorite variety of lead us to grow is right here and it's called Moire. We really like it because it's super easy to grow and it tastes really good. So it can take a wide variety of conditions. So if you have heat, It's really resistant to bolting. It seems to be able to take a wide variety of nutrient levels. So if you're not monitoring nutrients super closely, this one will do just fine. It also can handle different levels of lighting. So even when you have lower light, like if you have one off in the corner or something, it seems to handle that just fine. It stretches out a little bit, but it's still grows really nice. And then the flavor is probably the best out of any that we've tried. So the leaves get pretty big, which is nice. So you can use them whole like on a burger or something like that, or even use them as a rap. But then you can also chop them up really nice for solids. As I mentioned before, compact Romain can be really nice. So this is monte-carlo. And then there are hybrids between leaf lettuce and Romain like this one here is called fusion. This one can spread out a little bit more, but it grows really fast. Just nice. And then probably the most iconic hydroponic lettuce is the bib lettuce here. So this is one that can, it grows really well hydroponic Lee, the leaves are a lot different. There are really soft compared to the other one to two or more crisper have a crunch. So if you like the really soft lead us, this is a really good variety to curl. So if you're just starting out and you want to know what to start with just to get paying things. I would definitely recommend where, since it's so easy to grow. But once you get further along and you want to experiment, you could try basically any lattice variety you can find. The shorter the harvest period the better. So if you can find ones that get to full maturity by 50 days, that's usually good. But we've tried probably 25 to 30 different kinds of lead us and they all grow pretty well. So there's some, some pretty fun ones like red lettuce or other varieties like arugula that you can grow or even Swiss chard, which technically isn't lead us but grows very similar. So there's a lot of different things that you can try. I think it's fun to grow several different kinds next to each other. Because then you get a really cool looking system where you have different textures and colors all next to each other. 11. 10 Planting: Let us is a fairly simple crop to plant because it germinates so quickly. We've had lead US, Germany within a day of planting, and it almost always germinates by the third day. So within one to three days, you're going to have a seedling coming up. In our rail systems. We like to use the seed starter plucks for planting. So these are usually a mixture of tree bark and peat moss and it's bonded together so that it doesn't break apart and go through our system and clade pumps or anything. And these fit really nice into these 1.5 inch net cups. So then we can place this entire thing right into our rail system. Now works really well. When we plant, we put just one or two seeds inside of the seed plug. For moles varieties, you actually only need one seed because the germination rate is so high. You don't even need to bother with using two and then later pulling one out once they both sprout. Once we've planted the seed, we put this straight into our system. And the way our rail system works is the water level in the first rail is high enough that it touches the bottom of this C plug-in net cup. And that keeps this moist, cool Alfred, nice germination. So whatever method you do, It's important to keep this moist. You don't want it to be soaked or the siege could start to rot or suffocate. But you do want it to stay moist. And these seed plugs do well at holding moisture. This is our favorite method because it's so simple. All we do is put a seed in, drop this in our system. It can stay in our system the entire time. We don't have to move it between a separate germinating system and our main rail system. It just can go from seed to harvest. And then when it is time to harvest, we pull it out, we just have to break off the plant. And then this can be tossed or composted. And then that's all there is to it. The cleanup is really easy. Depending on the system you decide to use. There are many other ways that you could start seedlings. If you didn't want to invest much in supplies, you could just start seedlings in dirt and then gently transfer them from the dirt into your system. Other seed starting mediums you can use, there's rock wool. It's fairly similar to the C plugs we use. We just have found there'll be better germination and growth with these. But rock wool is an option. And then another one we've used is hydrogen. These are expanded clay pebbles. And these can work really well to grow lettuce in their reusable. But the disadvantage is when you go to harvest, you have to spend a little bit more time cleaning them up and then letting them dry out and everything. So it's a little more work, but it could save you some money. So those are a few options for starting seeds. And there's quite a few other options out there. One other note. Some people may ask, how is this different from dirt gardening when we're growing or seeds and something like this that looks very similar to dirt. Well, the answer is, the plant isn't getting much of its nutrients from this. There might be a little bit in here that extracts when it's a sibling. But the goal of this is just to provide moisture and a support structure for the plant as its first growing. But once the plant shoots roots out through the bottom, it's going to be pulling all of its nutrients from the water that's flowing underneath. So that's what differentiates hydroponics from growing in dirt. In this case. 12. 11 Harvesting: We're ready to harvest. This is where your hard work starts to really pay off. The first thing you'll notice is that it's still darks and the lights have been turned. Anya, I like to pick in the morning before the lights turned on for the day. Or if you're going outside before the sun starts to get very high. That's because during the night, the plants replenish the water that they lost the day before. Well, it was while the sun or while your lights run. So if you pick in the morning, you get crunchier juice here lattice. The next thing you'll notice is that a lot of these heads are pretty big. So these are definitely ready to harvest. Some of these are even bigger than what they need to be. But you can pick the lightest just about whenever you want. You could pick it when it's really small. But there's kind of a happy medium where the plant is bigger and has, had a higher growth rate, but isn't so big that it's either starting to bolt or starting to get kinda tough on the outer leaves. So just find that balance when you're picking. The other thing to mention is that there's two different ways you can harvest. You could take the entire head of lettuce when you harvest. Or you could just take the outer leaves and then leave the plant to grow more leaves and then take those in another week or so. I've done both methods. You can even combine the two where you take the outer leaves for a few weeks and then you take the plant. We usually end up doing more of the whole head lettuce because then we can take the whole head, put it in a bag, store it nicely or give it away or sell it. But you can do the cotton come again method where you're just taking the outer leaves. That could work especially well if you have a small space and you only have a few plants. If you only have three or four plants, if you're taking one head, it's going to be another week or two before you get another head. Whereas if you use cotton come again, you could have a couple of leaves every day if you need it. To demonstrate what I do for whole head harvesting. I'm going to take this head here and I just grab underneath, underneath the net cup and just gently lift. And then I pull it out and put it into a tray that I can bring up to the kitchen with a rail system. What we like to do after we pick a head of lettuce is we'll take a smaller head and put it into the spot that we just took the plant from. So in this case, these heads here to the left are smaller and they're actually closer together. It's hard to see in this angle, but they're pretty close together. So I would then take these out of their spots and put them into spots that are open from harvesting. And usually a system to rail system like this. I harvest four at a time. So I'd harvest maybe these four and then move these four into those new spots to give them more space to grow. After harvesting, we break the head of lettuce off from the base where the net GAAP and the seed plug r. You can do this give, giving a little twist can help to break it off. Then we just give it a little bit of a rinse to keep everything moist and you've minified when it's in the fridge. And then to store, we put them inside of a red bag. And they can stay in a bread bag in the fridge for up to two weeks. We found. 13. 12 Troubleshooting: Bitter Lettuce and Bolting: A common issue when growing lettuce is that it can turn bidder. In my experience, this is usually caused by the plant bolting. When let us bolt, it sends up a stem to begin flowering. And this is often triggered by high heat or along light period. When this occurs, the plant also turns a bitter taste, so it's something you want to avoid unless you're trying to grow lettuce seeds. Many varieties of lead us have been developed to be resistant to bolting, but it's still something that you want to watch out for to give you an idea of what it can look like. Here's a photo that shows bolting from when we first started with hydroponics. You'll notice the plants in the back and found a stem and our growing upwards rather than forming head. This is a classic sign of Bolding. Oftentimes, new growers will have this happen and they won't realize that this is something that shouldn't happen. So if you're seeing a stem on your lettuce, then that's usually not a good sign. If you experienced bolting or bitter lettuce. The first thing out work on is the temperature. I'd recommend getting the air temperature under 75 degrees Fahrenheit, if possible. Be aware that even if the ambient temperature is below 75 degrees, the temperature near the plants could be higher due to the heat released by the grow light. Especially if the light's not an LED. A fan can help move heat out from between Negro light and the plants if needed. If temperature control is not possible, I would recommend trying very bolt resistant varieties of lettuce such as malware. Another issue that can cause butter lettuce is letting it grow too long. Once the lettuce leaves get OLED enlarged and a decrease in flavor. So keeping irregular harvesting schedule can help avoid this. 14. 13 Troubleshooting: Tipburn: Fern is a fairly common issue when crawling hydroponic lettuce. And it's one that can have a variety of causes. Tip urn appears just as it sounds. The tips of the lettuce leaves look as if they've been burned or chart to diagnose the issue first, you want to pay attention to where the tip burn is occurring. Inner tip burn, which occurs just on New Girl towards the center of the head, is more common in my experience. Here's a good example showing inner tip burn. So you see in this plant, the outer leaves look fine, they're fully developed. But these inner leaves that are just starting there, clearly having trouble stretching out and growing and you can see the tips look like they've been burned or chart. So this is a classic example of inner tip burn. External tip burn, which occurs on the oldest leaves, can be caused by very high nutrient levels, where the nutrients end up pooling in the tips of the older leaves. But this is much more rare and easier to deal with an intertemporal lowering nutrient levels or harvesting the lettuce sooner usually fixes outer tip, burn inner tip, or it can be frustrating because it's stunts new growth ruins the appearance of the lettuce and it can cause the inner leaves to break down and be inedible. With inner tip burn. There's a lot of detail involved in what is happening and what is causing it. But in simple terms, the leaves are growing faster than certain nutrients, especially calcium, can be delivered to the leaf tips, which causes malformation. This could mean that your lighting is too strong. Giving the plant more energy than it's built in nutrient delivery system can handle. So basically the plant is growing too fast for itself. It could also mean that the humidity is too high, which slows down respiration mechanism that pulls nutrients up to the leaves. Oftentimes, this is just a pocket of high humidity near the lettuce, especially for dense heads that don't have open air flow to the core of the plant where the new growth is occurring. So one thing that can help with this as a small fan that blows air continually on the plants and pulls out any of these humid pockets that are forming tip. Or it could also mean that you have a nutrient imbalance. Even though tip earn is caused by a calcium deficiency, having too many nutrients can actually be an issue leading to burn. The plants react by absorbing nutrients at a faster pace. But calcium transport often legs other nutrients. Dropping nutrients to arrange between seven hundred and one hundred, ten hundred ppm can help if you haven't changed nutrients in awhile tip or it can also be a sign that it's time to do a nutrient change. Finally, take note that some varieties of let us have a much greater resistance to tip her. We found leaf lettuce is very resistant to tip burn. Whereas some varieties of compact Romaine or butter crunch with dense cores will be more susceptible to it, especially because they often cover up the core with their outer leaves. And so then there's that dense pocket of humidity can form or the new leaves are growing. If you notice tip or in, starting in some of your plants and make adjustments. Oftentimes the plants will grow new healthier leaves and it will be hardly noticeable. This plant actually had some burn, which we showed previously. But I let it, I fixed the conditions and let it keep growing and you can see it grew right out of it. So if you have a little bit of tip around, it's not necessarily the end of the world for the plant, it can grow past it. The new leaves that are coming in all look really nice with no tip or even with some tip burn, the lettuce is fine to eat. So don't get too worried if this is a problem you encounter. Just take some steps to mitigate it and you should be fine. 15. 14 Troubleshooting: Plants Stretching: A common issue when growing lettuce, especially seedlings, is have your seedlings look long and stretched out like Leckie, like these here. These aren't too bad. But you can see this plant definitely looks like it's stretching out. Like it's trying to get light. This one's just a little bit, just doing that a little bit. But if this continues, as the plant grows, the plant gets really skinny and doesn't add mass to a, won't get to maturity. So it could be an issue going down the line. So what almost always causes this is just lack of light. So if there's not enough light intensity, the plants are going to stretch trying to get to the light. So if you do encounter this issue, then you could either increase the intensity of your light or move the plants so that they're closer to the lights above them. However, when you're just starting, I wouldn't make any changes until you watch and see what happens. So these here, you can start to worry that these look laggy. But in my experience, as I move them down line, they're going to grow right out of this and we won't have to worry about it. So just seeing them at this stage looking a little bit stretched out, that's okay. But if they continue to do this as bigger plants, then that's something to be concerned about. So only only make adjustments to your lighting if you're seeing this continuous the plant girls. And one last thing to note, usually plants will look stretched out like this because of lack of light. Though sometimes it could be lack of nutrients. So if they're really low on nutrients, they're not going to be able to do the growing that they need. They're not getting nutrients to grow. So they could look stretched out then they'll probably also look off color, maybe a little more yellow if that was happening. So that's one other possibility, but probably 95 percent of the time, it's not enough light. 16. 15 Troubleshooting: Slow Growth: Slow growth can be caused by a number of factors. So you'll have to gather some more data to determine the root cause. Usually it's a sign that the lettuce is lacking at least one of its five basic needs. If the plants are lacking light, the leaves will be long and skinny almost as if they're stretching out, find more light. Adding more light should correct this. So either getting a fixture that gives off more light or putting the light closer to the planes. If the plants are lacking nutrients, the leaves will often have yellow patches or other discoloration. They could also look similar to when they're lacking light or the plant leaves are long and skinny. If this is the case, measure your nutrients and do a water change if needed. Here's an example from early on in our hydroponic journey. At this point, we had tried using water from our fish tank to do a sort of aquaporin IK setup. But this did not provide the nutrients that the plants need it. So you can see that many of the leaves here are thin and some of them are turning yellow. So we changed over to using regular hydroponic nutrients and that corrected the issue. Lack of oxygen in the root zone can be a major detriment to growth. If your roots are turning a shade of brown, this may be an indicator that root rot is occurring. So check out the trouble shooting video on root rot for more info on how to help with that. Low air temperature is another thing that can slow growth. But this is not necessarily a problem. It just increases the time needed to draw a full head of lettuce. And I haven't really seen much slowing occur until the temperature gets below 60 degrees Fahrenheit. So this isn't a very common cause. Similarly, low water temperature can also slow growth. This can be left as is, or improved with an aquarium water heater in the reservoir to bring the water temperature up between 60 and 70 degrees Fahrenheit. And finally, a pH below 5.5 or above 6.5. Prevent the plant from uptaking nutrients and slow the growth. And so this can look like the plant is lacking nutrients, but the nutrient solution might be fine. It's just that the pH is off and it's preventing the plant from uptaking the nutrients that it needs. You can check out the video on pH for more info on how to manage pH. 17. 16 Troubleshooting: Leaf Curl: One thing you may notice, especially with smaller plants, is leaf curl. Like here are the leaf is stirred and curl over on the edges. And I've seen this a lot, and I haven't noticed any correlation with negative results later on. So I think that's just something that the plants do and could just be a natural response to the environment or just stretching out when they're first growing. So if you see leaf curl, I wouldn't worry about it unless you have some other symptoms that are showing that plants having issues. 18. 17 Troubleshooting: Root Rot: Route health is very important for growing lettuce. Healthy roots will appear off white and feel firm to the touch. And the root should have lots of branching. If the roots of your plants appear brown and clumped together into a squishy mass. You most likely have root rot occurring, and this will slow growth or even kill the plant after some time. It can be a frustrating issue, but there are some simple things you can do to help. Root rot usually occurs in water that is low in oxygen and high temperature. Microorganisms called Pythium thrive in this environment and begin to coat the roots of the plant. Basically suffocating the roots, preventing them from uptaking oxygen and nutrients. To help root rot. Try to keep the temperature of your nutrient solution below 70 degrees Fahrenheit. Keep your nutrient solution reservoir out of the sun and away from heat sources as best as you can. And this will make the environment less favorable for Pythium to start colonizing your roots. Even more importantly, make sure your plant roots have access to oxygen. You can use an air pump to oxygenate the water directly. You can also allow some of the roots to have direct air contact and both of these will fight off route route. Once a plant has root rot, you can trim off the dead roots. Many times, the plant will shoot out new white roots after the conditions have improved. Otherwise, you can harvest the plant right away and start over with a new seedling. 19. 18 Troubleshooting: Pests: What's hydroponics? We can eliminate many of the normal garden pests just by growing indoors. However, there can still be pests, particularly bucks. I've had aphids or spider mites on my plants at times, bell for growing lettuce, it's never been a major issue. The bugs always seem to prefer sweeter plants like strawberries or other fruiting plants. Though if you're growing lettuce near other plants, you make it some crossover. In my experience, the best way to deal with bugs is to try and prevent them in the first place. So be careful about bringing plants outside and then back inside. Are putting outdoor potted plants near your hydroponic system for the winter. Something like that. Anytime you're bringing things from outside, inside, there could be bugs that are latched on and then you just introduce them into your hydroponic system. If you do notice bugs, the lattice will probably grow fine without any intervention. However, if the bugs bother you or if they're taking a toll on your plants. I found neem oil derivatives to work well. Just mix them with water and spray the foliage of your plants every week or so. After you harvest, if you are experiencing issues with bugs, you can soak your lettuce head in water for a few minutes and then I'll flesh out any bugs they're hiding inside. 20. 19 Demo: Nutrient Change: I'm about to do a full water change for the system. So I figured I bringing along to give you an idea of what it looks like for me when I'm doing a full nutrient change. So here I have a three rail system being fed by a 27 gallon reservoir. And it's been three or four weeks since I last change my water so longer than my original recommendation of two weeks. But like I said, it depends a lot on the system and you'll kinda, you'll get an idea for how long you can go. But so it's been a it's been a couple of weeks, three to four weeks. And I did a water top off in the middle, probably about a week or two ago. And you can see now I've turned off the pump. The water levels pretty low, around half or even a little bit lower. So definitely need some more water. And then I tested the ppm. It's not over a thousand was in the 800s, so still not bad. But I know at this point, given that it's been three to four weeks, I need to drain the water and put new fresh nutrients in. You can see the plants look really good. I am stirring to see a few little signs like here. I've got a little bit of tip around. So that's one sign where I can say, you know, I probably waited a little bit longer than I should have this time. It's not a big deal. These are going to be perfectly edible. But that's one sign that you can look at to say, Okay, it's time to change the nutrients. So what I do is I have I have my reservoir, I have a bucket here, and then I have a pump. So this pump is very similar to the ones that I use in my systems for circulating the water. This is, I think at 230 gallon per hour pump. And I always just have this one out and ready to do water changes. So I don't, I don't use the same poem that I used for circulation. You could, if you wanted, I suppose you could disconnect the pipe from this one and then connect the pipe from here to that pump and pump it out. But I found it easier to just keep one pump designated for water changes. And so then I also have a really long tube here. And the reason is from here, I can reach all the way to that utility sink. So I don't even need to use this bucket. But in the past, what I've done is you can just pump the water out four or five gallons at a time. So I put the pump in, pump the water into this bucket until it was full. Turn the pump off, take the bucket, dump it, and do that over and over again. Okay. So you can see I have one end of the pipe or off the tube going over my utility sink. And this side we have the pump. So I'm going to take the palm and just drop it into the reservoir, make sure it's near the bottom, the water. And then plug it in. And I'm gonna go ahead and start pumping water out. Like so. And so I'll wait I'll wait until the water is basically all the way out of the reservoir. You don't have to get it totally clean every time. So a lot of times I'll just get it so that there's an inch or two of water left. And in the pump won't really be able to do much after that. And at that point I can just add new nutrients if you start to get a lot of buildup of salts and things like you starting to see here. Then you could, once you get most of the water out, you could pull the reservoir out and dump it in and give it a quick spray and then start over with filling it back up. So either one depending on what's going on. But when there's some stuff on bottom of the reservoir, you don't have to worry about it. I haven't noticed any negative effects. So I'll wait here until all the water gets pumped out. Okay? So now the reservoir is nearly empty. So I'm going to mix up my nutrient solution to put back into the reservoir to fill it up. So since I have 27 yon reservoir, there's a little bit of water left in the bottom. I'll probably be putting in 20 to 25 gallons of water. So I keep them in mind what I'm mixing up my nutrients. And I can scale the recipe to shoot for that 20 to 25 on a monitor. So in this case I'm using a three-part nutrient. So I'm going to be adding this 1 first, get it all dissolved, then add magnesium sulfate and then calcium nitrate. I also use a little bit of vitamin C powder just to neutralize the chlorine since I am using city water in this case. And yeah, that's about all there is to it. So first, I will, I'll just show you one example of how I mix in the nutrients. And then it's pretty much the same after that. So I'll start by getting a tablespoon of first nutrients. Putting in. I need a tablespoon, does about seven gallons, so I'm going to do about three tablespoons. The nice thing is with lettuce. It's not essential that you get it exactly right. So you don't have to spend tons of time making sure that you get every number just right. So 2, 3. So I've got three tablespoons. Turn my water on. War monitor seems to dissolve the nutrients a little faster and easier. But I don't like to put real warm water into my system because I can start to cause root issues. So I just fill it about halfway with lukewarm water and then just use a stir stick and let it dissolve. And after stirring a little bit, add some more water to fill the bucket is full. And then I'll take this bucket over and add it to my reservoir as the first bucket of nutrients. On one thing, Dad, this is the point where I'd put the ascorbic acid or vitamin C, put it in, give it a little bit of time to neutralize the chlorine that's in there and then pour it in. I won't be turning the pump on right away anyway. So even once I put it in the reservoir, it'll have some time to neutralize. And then next, we'll just take the bucket and poured into the reservoir, then bring the bucket back in at more of the other nutrients. So I poured this bucket and the rest or next, I will do the Epsom salt. In the same way. I'll find the amount that I need for the 20 to 25 gowns. And I'm going even though this bucket isn't 25 gallons, it's just four or five. I am calculating for the entire amount that I'm adding. Because i'm I just added the entire amount of this mix that I'll need for the 20 to 25 gallons. I put that in just the first bucket. Now the second bucket that I'm putting in, I'm going to mix in this nutrient, magnesium sulfate and let that fully dissolve and then put it into the reservoir. And then for the third bucket, I'll put in calcium nitrate. But that fully dissolve, mix it in. And then at that point I can just add buckets that don't have any nutrients. I'm just adding water at that point to get the reservoir full to that 20 to 25 gallon mode. And that's all there is to it for nutrient change. For a nutrient top off, it's very similar except you're not actually pumping any of the water out. You're just doing this step where you're filling up the bucket. And then you can add like half the amount of nutrients that you need. At that point. Usually you don't need to add a lot of nutrients. The plants are often taking more water than they are nutrients. So you just add, do the same steps except with fewer nutrients and probably less water, you probably only need in my 25 gallon reservoir and probably only adding ten gallons, five to ten gallon teta nutrient top off in the middle of a cycle. But that's the full nutrient cycle. How I do it, It's pretty simple. This part takes me maybe 15 minutes and the top off is even less than that. One thing I probably didn't know earlier is I do turn off the pump when I do this. So this pump is off that let's the water drain back into the reservoir, back through this inlet tube. And so then you'll have is you'll have as much of the system, the water in the reservoir as you'll get. And that just makes the process easier. But then once I've filled up the reservoir and all of the nutrients are dissolved, then I will start the pumps backup.