Nutrient Mixing 101 | Hydroponic Reservoir Management | Grow Room Tank Mixing

How do you mix a reservoir? What do you need to mix nutrients in your reservoir? We will show you how to mix a hydroponic reservoir in this video.

How to mix a reservoir. There’s going to be two parts to this video.

So, Part one: A Synthetic regimen.

Part two: An organic regimen.

And we decided out of all the different lines that we carry, just to pick two to keep it simple. So first off, for the synthetics we’re going to be doing “GrowMore,” because it’s just going to be a three part, which is very familiar to what a lot of you guys are doing out there. Now, on a regular basis we get a lot of technical support calls with clients who ask:

• In which order do I add my nutrients?
• What should the pH levels be?
• Which component do I add, and which ones do I take out?

We’re here to address all of these questions, and give you all of the answers today.

So, let’s go ahead and fill up this reservoir! Once it’s filled, we’ve estimated that we have about 25 gallons here, which is what we’ll base our measurements from. Now, what I generally like to do for people is to underestimate my gallons, not necessarily put everything to the exact T. Now, the most common container, for example, is probably a 55 gallon drum, but generally I encourage people to take their measurements based on 50 gallons. Now, certain people are going to request other regimens; certain people are going to have their own special tricks that they do: but, what’s worked best for me is to measure for 50 gallons, even when I have a 55 gallon drum filled up.

That’s going to favor someone that’s going to be a little more conservative on their nutrient solution, as well as not running the risk of burning their plants. Now, we’re going to talk about a few pre-measuring tips that we like to encourage here at Monster Gardens.

First, you’re going to see that we have a recirculating pump down at the bottom. This is just a mag drive pump; the size of the pump doesn’t matter, but we do encourage you to use one large one if you only want to use a single pump, or a few smaller pumps if you can use several.

I’m using a 250 gallon per hour pump for the 25 gallons that I have here. It’s a really basic mag drive pump that’s just going to circulate the water; that’s all it’s really doing, to encourage any of those nutrients to not fall out of the solution, or rest at the bottom of the reservoir. Now, another thing to keep in mind, is that you want to have chlorine free water: at least, ideally, if you’re trying to harbor beneficial bacteria in your root zone. Now, what the chlorine is often found in city water, and most of your carbon or sediment filter devices are going to pull the chlorine, and ideally the chloramines, right out of the water. However, chloramines is actually the ammonium based chlorine molecule that’s actually pulled out of a KDF carbon filter.

You’re only going to see that on your reverse osmosis systems, with an upgrade filter option. Now, in the store here for our compost tea brewer, we have the Boogie Blue water filter—which is basically a carbon filter and sediment filter—that screws onto the end of a hose, and that’s what we use to fill this water. So, because this is not going to be feeding any organic garden in which there would be a lot of root inoculants, or a lot of compost teas being fed, we are not as concerned about using RO water. Now, for our customers that are using organic amendments—or are using beneficial fungal spores or bacteria—we encourage you to use a high end carbon filter that’s going to pull all the chlorine and the chloramines out of the water.

You can also do this by using a reverse osmosis water filter, but you need to keep in mind that you need to add that calcium and magnesium back to the water if you do decide to use RO water. So, for this instance, we are using tap water, but we’re using water that’s had the chlorine pulled out. So let’s go ahead and talk about a few things: so, at this time of year in the winter, pipes are a little cold, and the water that’s going to come out of the tap is usually a little too chilly for the root zone, but what we encourage for everybody is between 68 to 72 degrees. One more time: 68 to 72 degrees. Now, you may notice that your pipes are cold, so the water is going to be coming out well below that. So, that’s what we have over here: our very simple aquarium reservoir heater. Now, I just pulled one off of our shelf, and they actually come in a variety of sizes for different-sized reservoirs; this one here is a 200 watt, so it’s ideal for anything between 26 and 53 gallons. Now, that’s obviously a big range, so what it boils down to is: how fast do you want that water to be heated? Generally, I go with a medium-sized aquarium heater like this, and I leave it on most of the time, maintaining that temperature.

Now, we’re going to go in and close-up on this, and you’re going to see that there’s actually a little thermometer dial on there: that thermometer is not fully waterproof. It’s designed to actually be mounted vertically along the reservoir with the suction cups that are provided. Now, other all-metal versions of these heaters are going to be fully metal, or glass. This one is a glass one, but actually the top is also waterproof. For those of you that have purchased this, or are planning on purchasing this, don’t fully submerge this, or else you’ll void the warranty. So, that’s a really important thing, especially in the wintertime. You may be looking at your leaves and wondering, “why are my leaves yellowing?” Well, it could be a number of things, obviously:

• Your pH could be off
• Your room could be too cold
• Or, you could be missing certain elements from your nutrient regimen

But the big ace that’s under everyone’s sleeve that gets overlooked is the temperature of the water. Now, in the wintertime, especially if you’re in an open air system—or if you have concrete floors in your garden—your roots-on may be chilly; especially in the nighttime when the lights are off. So, keep in mind that when you’re feeding plants at the right water temperature, it’s going to allow those nutrients to be taken up much more evenly, and especially easy for the plants. Now, time and time again, people come in with nutrient deficiency problems, even when they have a complete nutrient, so, being able to root out water temperature as a factor is a really good thing. Now, most of the meters on the market, such as this blue lab combo meter here, will actually give you a digital readout of the temperature. That’s a really good tool to have in your gardens. Along with a very simple mercury thermometer that’s going to float in your reservoir, and tell you the temperature, this is going to give you a precise, digital readout, so that—not only are you going to be able to read your pH and your parts-per-million—you can also get the temperature of the solution. That’s very important.

Another important thing to keep in mind before you add any nutrients to your water, is what is the parts-per-million to begin with. Some people talk about hard water or soft water: here at Monster Gardens, we classify hard water as generally anything above three to four hundred parts-per-million. It’s not as common in city water, because the city has a very good way of maintaining the level of calcium magnesium and iron that;s in the water—so generally, the parts-per-million are going to be under 300—but in well water, you’re going to see the hard water. They do make water softeners to address that, or obviously the carbon filters are going to pull out some of those minerals from out of the water. The important thing to note is that a lot of companies do make a hard water option for their micro, which is just going to contain a little less calcium, and alcium is the main thing that’s reading the high parts-per-million.

In very warm environments, or strains that have a tendency to have stem breakage—or ones that simply can’t hold the heavy flowers once they get late into flowering—potassium silicate is a really common solution. Many gardeners have had them in their regimen, and don’t even necessarily know what it does. The thing about that, is that it’s going to increase the size of the cell wall on the stock itself. So, it’s going to allow for more nutrient uptake, but more importantly, it’s going to give you this kind of woody, rigid look to the stalks. So, the plant is actually going to be stronger; it’s going to hold that heavy weight. It’s going to be able to withstand drought, or a lack of watering, or even a heatwave that might roll through. So, especially you outdoor gardeners growing in the warmer areas, such as Central Valley, potassium silicate is a must. You really want to be giving your plants potassium silicate in some form, because it’s going to bulk the size of the plants, and prevent future stem breakage, or even plants keeling over and dying because you missed a day of watering.

This is important for Hydro people, too, because you’re relying on a pump most of the time, so it’s really important to have a little extra armored coat for your plants. Give them that strength that they need. Now, what most manufacturers don’t tell you, is that potassium silicate has a pH of around 11. A pH of 11, going into a nutrient solution that’s going to be under 7—that’s probably going to lock out most things.

Now, when you pour the solution it’s going to seem real milky, and so the average gardener—or at least someone that’s new to this—is going to see it cloud up the water with everything else in it, and wonder, “that looks very milky; that’s a very thick solution.” Well, the really big thing that’s going on, is that your nutrients have just locked out and sunk to the bottom of the reservoir. It’s because it’s such a drastic shock of a high pH going into a mild to slightly acidic pH that’s already in the water. So, indoor gardeners—-and outdoor gardeners, for that matter—always encourage potassium silicate to be added first.

Now, everyone knows the adage “micro first,” unless you’re using RO, in which case you’d add cal-mag first: however, potassium silicate needs to go in before all of that. Make sure it’s mixed in very well before you add anything else. Any random pockets of a high pH will lock out certain elements, so over stir your potassium silicate, then add it first.

So, we’re sitting here over our reservoir—going over a mental checklist—and you’re looking at the water and thinking, “man, I’m excited to feed these plants.”

1. Temperature is right (between 68 and 72 degrees)
2. Measured parts-per-million
3. Know whether or not to add cal-mag, and how much
4. Have all of the nutrients waiting on a shelf

I like to encourage everybody—especially since most of you are mixing at around 7, or 8 p.m. at night, when most hydro stores are closed—is to go through all of your bottles and make sure that there’s a little bit of liquid in all of your solutions, and to make sure that there’s at least a little bit of liquid in all of your bottles, so you don’t run out: the last thing you want to do is to get halfway through a reservoir change, and then run out of micro or bloom.

You’ll definitely want to stock up on a higher size. Visit Monster Gardens.com, and make sure you replenish your nutrient shelf.

Start Mixing

We’ve gone through our mental checklist, and we’re ready to start mixing. I’m going to first grab the potassium silicate—this is a really great one from Grow More, because it’s extremely concentrated. Now, potassium silicate is oftentimes pretty thick, especially when it's as concentrated as this one, so I always like to give my nutrients a big shake. Now, I like to really go for it. I’m a big “shaker” kind of guy; kind of like it’s a salad dressing.

Like I mentioned earlier, this is a 25 gallon reservoir. This is my favorite measure beaker to use, because it has the different elements, and it’s on all sides. Pick your favorite beaker, because mixing nutrients is one of my favorite things to do, so pick a friendly beaker and go with it.

This one is 25 gallons. Read the bottle before you start going. So, this one here is 5 mils per liter, which means it’s actually going to be 20 mils a gallon. This is a 25 gallon reservoir, so when you do the math, that’s 500 mils. All right, so we’ve got it all poured out. Remember, potassium silicate goes in first, but you’ll want to dilute it. I’ll pour it in the water like that; I don’t just dump it right in, I actually dilute it first. Okay, I usually clean out my little beaker a couple of times, and that will encourage the solution to be diluted before it just pours right into the concentrate. It’s not as important on your first few bottles, but definitely once more and more nutrients start getting added to the water, you always want to make sure and dilute. So, I brought a little stir stick around just so that I can make sure that silicate is really well mixed before everything else is poured. Like I mentioned earlier, if there’s any little pockets of silica, it’s going to be a little high pH floating around. It does a very good job at diluting itself in the solution, but the last thing you want to do is lock out some of your micronutrients, because that’s the next thing that’s going into the batch. We’ve got a really good mix going on; I generally like to get a bit of a vortex swirl. Now, micro always goes in first, unless you're using potassium silicate. The reason why you always want to add micro first, is because it has the most sensitivity to the pH. Also, the big thing to know about this, too, is this is what's often going to make your water back normal again. A lot of times people are starting with RO water and they have a clean slate. Really just hydrogen and oxygen in the water. So this is going to allow you to add more of an equilibrium when it comes to calcium, magnesium, and iron back into the solution here. And you’ll notice this micro is red, and that's because it has a lot of the iron in it. But also, this particular Grow More micro, has a little seaweed in it as well. That's what's going with that dark, thick color. So especially with the Grow More micro, make sure and shake it really well. So you don't get that little layer of seaweed at the very bottom. I’ve had a couple of people lately come back, just wondering what that was, because they haven't seen that in the G.H. Floor Micro. But, this one has a little additional seaweed added to it. So definitely make sure and mix it to get the most bang out of it.

Now, this micro is five mils a gallon. Very concentrated. Half of the industry standard. So, what I'm going to go ahead and do is go to the millilitre side. We have 25 gallons in here. So, that's one 125 milliliters. Go ahead and just set this down so I can screw my micro back shut. I always like to screw the caps back on as quickly as I can. No contaminant land back into the bottle, and right back onto the nutrient shelf. Now, you're going to see it a lot easier with this one than on the silica. How do I dilute it before I dump it in? I just pour. I let the water get in, dilute it in my beaker cup, and then I basically just dump her on in. No reason to be in a rush when you're mixing up nutrients. You want to make sure that all of these things are in the solution evenly. You always want to make sure that they're in there at the right concentration and at the right pH level, because this is what's going to be fed to your plants. So give them the right amount of nutrition at the right pH level, and make sure it's all mixed in really well. Now it's time to add your Grow and your Bloom. Now, you viewers out there, you might be wondering, “well, gosh, I don't use a three part, and I certainly don’t use that particular one—what do I do with my baby?” Well, if you look at your A vs. your B, you’ll notice that yours has a very thick, dark color, and your B is often going to be pretty clear, if not perfectly clear. The reason why you’re going to see them having different colors, is because your A has your micro in it. The same principle for why you add the micro first, is the same reason why you’ll want to add A before B. You always want to add A, mix really well—just like your micro; always want to add your micro, and mix really well—then you add your B.

What’s in a B?

Your B is basically going to be a combination of your growing bloom. Oftentimes, it’s a little bit more of your bloom, because more growers phase their grow out when they get into the middle, to late flower. So, we’re going to go ahead and mix a transition reservoir. If you look at the feeding chart on a transition stage, you’re going to see it’s going to be equal parts, which on Grow More, is going to be 5 milliliters of all micro grow and bloom. So just for simplicity we’re going to mix the same reservoir. We’re transitioning from growing to bloom.

5 milliliters per gallon per 25 gallons: let’s go to 125 milliliters.

All right, so we’re going to go ahead and dilute this in there. I always like to use a very heavy-duty stir stick. Some people like to use the blue lab truncheon. I don’t really like the idea of that because it’s a very expensive stir stick. Instead, I just use a simple bamboo stick. It works fairly well—I just don’t like to keep it in the reservoir because they are often hollow and can harbor pathogens, or any anaerobic bacteria that doesn’t correspond well at the root zone. I want to encourage you to keep your stir stick outside of the reservoir if you’re using a bamboo stick. All right, we have our grow mixed in there with our micro and our potassium silicate, so now it’s time to add a little bit of bloom. Many people are going to be using a Lucas formula: a micro in bloom solely, and they completely cut out the growth; which is totally fine, but I find for a longer vegetattive growth, it’s really important to use your grow as well as the bloom.

Quick Veg

So, it’s only going to work for a quick veg—if you’re vegging for any longer than say, four weeks, you’re probably going to want to keep a little bit of grow in there, or at least a supplement with some kind of extra nitrogen. Nitrogen is very important for foliage development, as well as stem elongation. If you’re just simply topping your plants a lot, you’ll need to give them enough nitrogen so that they grow new shoots quickly. I very much encourage you to use all three parts: however, you can get away with just the micro bloom—but really only if you’re using a short flower, especially a short veg time.

So, what we have here is the bloom; it’s also going to be 5 mils per gallon, because we’re doing the transition formula. So that’s going to be 25 milliliters. Now, you’re going to see this one’s really clear. They like to add dyes into their three parts, so that way if the company’s have workers that don’t speak English, or people that are better visual learners, colors are a really easy way to do it. That’s why many companies throw dyes into their solutions; it’s not to be cheap, it's not to put an extra filler into their solution: it’s really just so that the workers down the line can tell the difference.

So what we did here is we added a little bit of bloom to it. And once you're going to notice our nutrient solution has actually gotten a little bit lighter. And really, it's just because we're diluting a little bit more into it and the pH is changing slightly.

All right, so the last thing is a little bit of Cal-Mag. Many people look at me like I'm crazy because I don't add my Cal-Mag first. You can. You definitely can. You could go potassium silicate, Cal-Mag, micro, and so on and so forth. However, the reason why people like to add Cal-Mag first is so they know where they're starting with. When you're using reverse osmosis water, you're going to be starting with a clean slate. Most likely zero parts per million. That is, if your carbon filters are new. So, say you're starting with zero, or anything under 10 parts per million, and you need to add roughly 250 to 300 parts per million of Cal-Mag. That makes it very easy to just add this first. You go from zero to 50. Boom. Cal-Mag is taken care of. You can just as easily add this at the end of your regimen. If, say, you measure your parts per million and you're around 900: well, if you want to get it up to 1150, you can add 250 milliliters of Cal-Mag in there. That's totally sufficient. But, for peace of mind, most people add this first. But for this video, I'm going to go ahead and show you guys that it doesn't matter, you can add it at any time in your reservoir as long as it's in there, because calcium magnesium is very important. So, for this mixture here, this is actually going to be a measure from two to four milliliters per gallon.

So, what I'm going to go ahead and do is just do the full strength just so that it's a little bit easier. So, 4 milliliters to the 25 gallon reservoir: that's 100 milliliters total. So what we're gonna do here is we're going to go to the hundred. Now, what you're going to notice on a lot of the Grow More products, is that they're slightly more concentrated than the rest. They do this because they're a big Ag company, and it makes it a lot easier for them to bottle more concentrate; that way, in the end the user is actually getting a little bit better of a deal. Now, as we talked about, this is part one of our video. This is going to be a synthetic regiment. We are soon going to show you how to mix an organic regimen, but that's going to require a few different extra steps. And the big thing about that is going to be additional stirring, whether it be stir pumps or just additional stirring in between bottles, because things are a little heavier. They have a tendency to fall out of the solution. But for this particular video, with the synthetics, things are pretty thin. They only really need one single stir pump and an occasional stir just to make sure that things are mixed in. Well, but as you can get a close up on this, I mean, this water is pretty darn thin.

I mean, it's really quite thin.

Granted, Grow More is known to be a low-salt nutrient company, so that might be attributing to it. But, gosh, I mean, this would run great through drip emitters. This would run great through any type of flood and drain in any type of a top-feed system. I mean, this would be a great solution for really any type of a setup. Now, the big thing to keep in mind, though, is when people are running hydroponic systems, or synthetic nutrients in general, is generally you're running either a sterile or you're running a biological approach. So, you're either taking a sterile approach or a biological approach. Now, when you're taking a sterile approach, oftentimes you're not using things like hygiene, peroxide. So that way you're gonna kill off any bacteria, whether it's beneficial or not. Most of the time people are gonna be using a hygiene peroxide type solution. And what that's going to really do--just like a sore on your arm--is it's going to kill off any bacteria. Now, that might be beneficial bacteria, or it might be pathogens. You've just got to keep in mind that when you're running a hydrogen peroxide solution in your nutrients, or to clean systems, it's going to clean everything. So if you're running an organic regimen, or if you're running with a biological approach, I definitely encourage you not to use hydrogen peroxide, because it will wipe out any colony, and you'll be forced to reinoculate right after that. However, for this particular segment of video, we'll talk about more of a sterile approach, which is going to be common in a deep water culture. Deep water culture: you're going to be cycling nutrients like crazy through all of your buckets. A lot of times these things are daisy-chained together. A lot of times it's just all in the same nutrient solution, and there's not much of a buffer at all between the fertilizer and the roots itself. So, it's important to keep things sterile, so that way no anaerobic bacteria is forming in there. That way there isn't any random slime that can be forming on your roots or in the random pockets of your DWC system. Hydrogen peroxide is very commonly run through a system like that. And the reason is? Just keep things sterile. Like I said, just like you would on a cut, but also you're adding additional oxygen in there, which is going to be beneficial for root growth. Now you can run the same exact nutrient solution with a biological approach, because all you're going to be using is a lot of beneficial bacteria, such as Serenade, or such as the ones you'll find the OG Bio War, such as Sea Green.

And what those are gonna do is be these beneficial bacterias that help consume anaerobic bacteria. Or they help dominate them in the same way that a white blood cell would for a pathogen in the body. So, you want to have these beneficial organisms that are going to fight for you. It can be very difficult, though, if temperature gets out of whack—or if your nutrient solution is out of whack in any way—those anaerobic bacterias may be a little bit more dominant in that root zone. So, for any type of synthetic regimen, or any type of hydroponic regimen, we really encourage you to take the sterile approach. However, it is definitely possible to go with the biological approach; I would just definitely encourage you to use those certain products that we talked about. So as far as nutrient solution temperature, like we talked about earlier in this video, it's mostly crucial in a hydroponic system. More specifically, the ones that are going to be submerged in the nutrient solution, such as a deep water culture or a flood and drain type situation. I definitely encourage the reservoir heater, so that way you can maintain the right temperature. So, let's go ahead and let's measure the pH in the parts per million of the solution here.

So what I'm to do is I basically press the "on" button, and put both the probes in. As we talk, it's always encouraged to store your pH meter wet, just to encourage the most accurate reading. Again, about pH monitoring, you always want to make sure that it's calibrated. Most meters will still tell you if it's calibrated or not, or if it needs to be. However, twice a month for maintenance is definitely encouraged. That's going to make sure that the life of your meter is going to be the strongest. And you're not skipping any waterings, so that your plants aren't getting a false reading. You always want to make sure and move your meters around for the most accurate read: the last thing you want to do is have a little pocket in that water that's reading a little higher of the nutrients, or reading a little low or high on the pH. So, I encourage every grower out there to always move your meters around for the most accurate reading. You can see we're mixing a transition reservoir, so a pH of around 6 to 6.3 is very ideal. Granted, if you're in a coco fiber medium or you're on a recirculating system with Rockwool, that has a tendency to raise the pH over the course of the week; most people's pH is around 5.5, to 5.8. I still encourage for the most nutrient uptake to be between 6.0 and 6.3. You can see this reservoir, at 6.2, is pretty ideal. And then we'll just press right over to the nutrient, and it's reading; 1300, 1280, 1290. Right in that range. So, I'm going to set my meter down, and then you can just pull your probes right out the solution. However, you want to go right away and you want to put your pH meter right back into its case, so that way, you know it's being stored wet. Parts-per-million meters are pretty indestructible. However, I still encourage everyone to keep them cleaned. Calibration will still probably want to be right around once a month, but you may notice that your calibration is always gonna be on point as long as you're keeping your meter cleaned. All right, so now that you have your nutrient solution mixed, you know that your parts-per-million isn't too high, that your plants are going to burn. You know, your P.H. level is set right where it needs to be for proper nutrient uptake. Now, let's talk about a few things that I didn't add to this reservoir that might make this a little bit better. I encourage everyone to use a fulvic acid full. Fulvic acid is going to help a lot with that uptake of the micro nutrients. Notice that the fulvic acid by BioAg, called "Full Power," is the one that we endorse--you'll see in some previous videos--and that one is not going to fluctuate your pH at all. However, it does have a very minute parts-per-million increase, but it is maybe about 10 to 20 parts-per-million, so it's not going to really drastically affect your plants. If anything, you're probably going to want to kick down your application rates slightly. That's going to allow for more nutrient uptake a lot quicker. So if you're feeding your plants, say, a 1280 parts-per-million solution, you may want to kick it down a little below 1200—if you're using a fulvic acid—just so you don't burn your leaf tips.