It’s time for me to start a new diy aeroponics project. Recently I added a new grow room so I needed a new system. I have been growing with my homemade aeroponics diy system for a couple of years now and it works very well. But I decided to take what I have learned and build a new system for both my grow rooms.
Also because there are not a lot of high pressure aeroponic tutorials I thought it would be a good idea to post a how to guide. So if you are considering aeroponic growing and want a high pressure system this is for you!
I find plants grow faster in aeroponics and I get more resin and better smell too. Still, I wanted to give growing in coco a try again. It is how I started growing and I wanted to try some additives that are not compatible with aeroponics. In my new grow closet I wanted to get off to a quick start I set up a grow in coco beds while I was planning out this system. But after a few grows I can truly say nothing beats high pressure aeroponics for growing weed.
You don’t need to spend time messing around with grow media which is a big time and money saver. Media can also bring in pests and or give them a place to live. You use much less fertilizer and much less water which is another bonus to aeroponic growing systems.
I like to keep things simple and this will be a basic high pressure aeroponics build. People like to over complicate aeroponics and it seems to draw techie and engineering types.
You don’t need to be a NASA rocket scientist to grow aeroponic weed. All you need is the right pump, timer and misting heads. Use good clean nutes, a filter and add electricity and you are good to grow.
Just remember we are here on earth growing weed. We are not in space and not going or growing on Mars so don’t fall for all that stuff that says you have to do things NASA’s way or it’s not true aeroponics. They didn’t invent aeroponics and their systems are designed to grow small plants like lettuce and other greens with a fast turnover.
You can add solenoids and accumulator tanks if you want but they really are not needed. I think the more complicated you make things the more likely something will break and screw things up.
If you want more info on aeroponics, its origins, future and current growing methods you can check out this article.
What Is Aeroponics?
Aeroponics is a specialized form of hydroponics. Instead of using grow media or submerging roots in water like regular hydroponics the roots hang in the air from net pots and are sprayed or misted at intervals.
There are 2 types of systems, high pressure and low pressure aeroponics. Both work very well but high pressure systems will give better root development and increase nutrient uptake as well as reduce the amount of nutrients needed.
The main difference between them is the pumps that are used. Low pressure systems use a high volume of water, often over 400 gph, and low pressure pumps usually are rated under 5 psi.
They can not deliver a fine droplet size but they are easier and cheaper to build. They are often built using PVC pipe or square fence posts and many of these are actually NFT/Aeroponic hybrid systems.
They are a bit cheaper to build and less likely to clog because of larger orifices. They are more forgiving and if you are a newer grower they may be a good place for you to start.
High pressure aeroponics systems are the exact opposite. It uses a pump that can deliver about 2 gph but at pressures 80 psi and above. The nozzles used can deliver a very fine mist.
Because of the higher pressures it is necessary to use specialized fittings and this is what makes these systems cost more. Smaller sprayer orifices make clean water and nutrients absolutely essential to prevent clogging. Plants grow very fast but things can go wrong very fast so high pressure aeroponics is not the best choice for newbies.
In this tutorial you will learn how to build an efficient yet simple high pressure system that will grow the best weed you can imagine. Before we get into the build itself we need to go over a few things.
What About Water?
Water is the most important part of any hydroponic or aeroponic system. If you already grow hydroponically you probably already know this.
You will need to use reverse osmosis water unless your tap water is very clean. If your water tests much over 100 ppm on a TDS meter, or you know it is hard or it has been softened you will need to use RO water.
I am extremely lucky to live in an area where my tap water tests at 29 ppm, but in most places it runs over 200 ppm. This also means having to add a calcium and magnesium supplement because it is not present in either my water or in RO water.
Fortunately the system I am showing you to build doesn’t require anywhere near the amounts of water required by deep water culture, ebb and flow or other systems. If you need RO water you can set up a small system. Some aquarium stores also sell reverse osmosis water.
Because high pressure systems use nozzles with small orifices it is crucial to keep your water clean. You will want to guard against dirt getting in the reservoir and to your nozzles. Inline filters are available and easy to clean. I also use a 50 micron felt filter bag over my water intake.
DIY Aeroponics Pumps – Choosing The Right Pump
I really like Aquatec pumps for a number of reasons. They are reasonably priced and very sturdy. You can even run them dry, but I wouldn’t. They also are quiet. They are the only pumps of this type made in the US too. But there are a lot of models and choosing the right one can be confusing. You don’t want the Aquatec 6800 series. These are transfer pumps and put out lower psis.
What you want is the Aquatec 8800 series which are booster pumps. These can be run at 130 psi and there is a model that puts out 150 psi.
They run on 24 volts so you need a transformer to run them. Some venders sell them with the transformer and some sell it separately.
Some have adjustable bypass settings and this is what you want. Pressure can be adjusted with a 1/16″ allen wrench on the front of the pump. You need to have a pressure gunge hooked up if you are going to try this.
Here is the pump that I recommend:
This pump will work great for most projects and I am using it for cloning and vegging. It will run multiple flowering totes too. But for larger projects, 4 totes or more you may want this 150 psi pump. This is what I am using in my flowering totes. Certainly the 80 psi pump will work and you can adjust the bypass on it but Aquatec says to run these pumps below 132 psi so I am guessing the larger one can run at 160 psi because it has a different diaphragm. The more nozzles you run the more pressure drop you have so a larger pump with a higher psi rating will keep droplet size smaller.
You are going to need a short cycle timer that can be set to run from several seconds on to several minutes off. These are specialized and unfortunately they are not cheap. Regular timers work on 15 minute on/off cycles and this is way too long to make them usable.
I use a digital CT 1 timer. It’s a rip off at almost $100, but the only other alternative is the Apollo 15 which costs over $150. With digital timers you can set intervals exactly and you have a read out showing you what the cycle is.
You can get some analog timers for a bit less. But they cant be adjusted as precisely and knobs can get bumped into and moved accidentally, often with disastrous results. I also bought one of these:
|Titan Controls Short Cycle Timer w/ Photocell, Single Outlet, 120V - Apollo 12|
total customer reviews...
It works pretty well and cost less than the CT 1 but it is harder to set exactly. No complaints though really.
I have heard of problems with CAP timers so you might want to avoid them. Also I found this on Amazon and if you are an electronics diy person you may be able to make this work for you and it is under $30:
|Inkbird Digital Twin Timer Relay Time Delay Relay Switch 110-220V Black IDT-E2RH|
54 total customer reviews...
I might have to buy one and see if I can figure it out but I am not familiar with wiring stuff together so I prefer plug and play. If you are electrically inclined you can probably build your own timer and there is a diy aeroponic timer tutorial here.
No matter what timer you choose make sure it is set to run day and night. If your timer is set to only run 12 hours you will probably wind up with dead plants.
Misting Cycles And Droplet Size
Some aeroponic growers run extremely short misting cycles like 30 seconds on or less and about 2 minutes off. If you are going to run a short cycle like this an accumulator tank will help save wear and tear on your pump. But the pumps I use and recommend are rated for over 30,000 hours of continual use and can even be run dry.
At about $100 a pop I think it’s cheaper to replace a pump every 3 or 4 years than to create a more expensive, complicated system to protect them. Also a malfunctioning pressure relief valve can turn an accumulator tank into a bomb.
Your pump is the life blood and heart of your system so it is a good idea to keep a spare for back up. If a pump dies you will have a hard time finding them locally and shipping takes time. If an emergency arises and you have to pay for overnight shipping you just about bought a new pump twice anyway.
You will want to keep some spare misting heads too so if a clog develops you can change them. I am using preassembled units as you will see later but you only need to replace the heads themselves and not the whole unit. Also over time performance will deteriorate because of every day wear and tear. It is probably a good idea to replace nozzles yearly.
In my old system I have found 1 minute on and 5 minutes off is a good starting point. You want to get all the roots watered but you also want them to get oxygen so you want them to be only slightly damp when the next cycle begins. You can adjust the cycle by feeling the roots inside your tote. Obviously smaller roots will need less misting time than larger mature ones.
I have been testing this system and because I am running 3/8 instead of 1/4 tubing it delivers considerably more water. I am running young seedlings with fairly small root systems and now going 45 seconds on and 5 minutes off. I am considering dropping it to 30 seconds on. I might look at increasing the off cycle a bit too.
Your roots should be showing a fish bone pattern when grown in aeroponics. This White OG has it but honestly I have seen better examples. This reinforces my idea that at the very beginning these plants were getting too much water. There are some straight roots that look more like regular hydroponic roots.
There are no hard and fast rules for cycle times so experiment and watch your plants closely. I like the idea of using longer off cycles because it is easier on the pump.
This brings us to the question of misting heads and droplet size. According to NASA 50 microns is the ideal droplet size for nutrient uptake. This doesn’t mean that plants can’t use larger droplets though. That is why low pressure aeroponics can still grow excellent plants.
I use Tefen misters with droplets from 50-140 microns. I am using a 150 psi pump so I expect my droplet size to be smaller. Larger droplets are beneficial for your crop too. As plants grow the hanging roots get pretty thick and smaller droplets would have a hard time penetrating to the center, but the larger droplets can.
If I were a plant I would want my roots in this! I think my diy aeroponics system can produce a fine enough mist to grow anything. Wouldn’t you agree?
Setting Up Your Grow Room
Before you start it is always a good idea to plan for the unexpected. Where there is water there is always the potential for leaks. Fortunately high pressure aeroponics uses much less water than other hydroponic systems. I will only be using 10 gallons but if you have ever spilled even a gallon of water you know how it can spread.
I lined my closet with pond liner. It is tough and durable like an inner tube. I stapled it so I have 6 inches of height which should hold well over 50 gallons of water. Don’t be tempted to use plastic because it gets holes in it easily. With the pond liner there are no worries and you can walk on it and move things around on it. You can get it at some gardening centers and I think even Home Depot has it on a roll.
For my set up I just took some 3 gallon pots, set them in the corners and laid my boards on top of them with a space in the middle for the drains. My reservoir will sit under the boards.
You’re Going To Need These Totes
Head over to Lowes and grab as many of these Centrex Plastics, LLC Commander 27-Gallon Tote with Standard Snap Lid as you need.
They cost $14 and are worth every penny. They are super heavy duty and measure about 30.8 inches long, 20 inches wide and about 15 inches tall. A bit shorter in height than the original Rubbermaid totes I used but overall much bigger and about 3 times thicker.
Home Depot has a cheaper version of this tote and although they show the same picture the totes are actually different. Theirs is smaller and has a diamond pattern on top. A hole for a 3″ net pot is slightly larger than the squares on these so I would only want to use them for 2′ pots. You can use them with 3″ pots but I would go with the ones from Lowes because cutting out the lids will be easier.
Cutting Out The Lids
The lid has 35 squares, you can use as many or as few as you like. You can either use 2 or 3 inch net pots. I prefer the 3 inchers because the plants are more stable and don’t fall over as easily. You wont be able to use all the squares if you use 3″ pots. I chose to do 10 per lid. I am building a 3 tote system and want 30 plants in my 2′ x 8′ grow closet. For large plants you may want less but you can always add more later and you can plug unused spaces with a net pot and insert or even a party cup.
It is important to realize that a 3″ net pot will fall right through a 3″ hole. On my last project I used a 2 7/8″ hole saw and it worked perfectly. However for the squares on this lid I used a 2 3/4″ hole saw I got at Lowes. The reason being that the squares are raised and the larger saw removes more of the sidewall than I like. But the 2 3/4″ hole saw leaves a hole a bit too snug.
So I reamed them out with a deburring tool. Couldn’t find one at Lowes, Home Depot may have them or you can get them on Amazon here. It will get rid of sharp edges, smooth out your cuts and make your net pots fit like a glove.
The perfect size hole saw for this lid would be 2 13/16″ but I am not even sure anyone makes them. Don’t sweat it though any of the other 2 will work.
If you are using 2″ pots you will probably want a 1 3/4″ hole saw and they are available at Lowes.
One thing I found was that you need to have enough clearance between the hole and the reinforcing that goes around the inside edge of the lid, especially on the ends of the middle row. If you drill too close the rim of the net pot wont go all the way down so make sure you drill as close to the outside edge of the square as you can. Please don’t ask how I know this! Here is a pic of my finished lids.
Drilling Out The Tote
I have drilled a hole on the side of the tote for a 3/8 bulk head using a 5/8 inch spade bit. This is where the feed line will come into the tote. I like to use a 3/8 inch stem elbow on the bulk head. The 3/8 tubing I am using is flexible, but I feel like using it makes it easier to hook up to the tote and helps keep pressure off the bulkhead.
You are going to need to drill a 1 1/8″ hole for a drain. That works for my 1/2 inch fittings anyway. I am using 3/4 inch fittings this time and they need a slightly larger hole, but a few passes around with the deburring tool makes them just right. Probably it’s best to measure yours because there is no standard size and each manufacturer is different.
I am putting mine on the bottom of the totes. I am using a reservoir directly underneath my totes. The totes will be resting on 2 2 x 8 boards spaced 2″ apart on the center. They will drain into my reservoir that is directly underneath them. You can drain out the side too if you want.
Here is a top view looking into the tote. You can see because of the way these totes are molded that you have to offset the drain if you are coming out the bottom. Don’t panic, I will cover the misting heads and set up further down in this tutorial.
I am doing this partly to save space but also because the tote bottoms need to be higher than the water line in your reservoir to drain properly.
I built my old aeroponic system drains with 1/2″ tubing and fittings and had a few clogs so this time I am using 3/4″ drains. These are the bulkheads I am using. They have a barb on the outside and are threaded on the inside. You should be able to get them at any hydro store or you can get them here.
The threaded inside is nice because you can add a fitting inside if you want to retain some water in the tote bottoms. This acts as a safety for your plants in the event of a power outage and can keep roots out of your drain lines too.
The truth is no matter how tall your tote is the roots will eventually hit bottom anyway. So forget all that crap you read about roots having to totally hang in the air.
Setting Up The Misting Heads And Totes
I am using tefen misters and have found a really cool set up for my nozzles. The nozzles come in a pre threaded tee with quick connect fittings built in. They also come with a mounting bracket.
They were designed for misting produce and are made by a company called ProDew. One of the things I like about these misting heads is that they are dripless.
Obviously supermarkets want their produce moist but don’t want water dripping on their customers.
My old style misters would take a few seconds to start spraying and would drip a bit once the pump was off. But with these bad boys the second the pump kicks on they are spraying and the second it shuts off they stop.
The nozzles can be shut off entirely and the built in wrench makes removing them a snap. Before I would have to reach in with a wrench or vice grips to change or clean my nozzles. Now I can unscrew them without any tools.
I found them in Amazon store called Pro Water Parts and they are being sold singly or in packs of ten. They come in black or white. They are only available to use 3/8 tubing.
Lately these seem to move around on Amazon. Pro Water parts inventory changes but you can find them singly or in 10 packs at Tefen
This store also has most of the fittings you will need and RO stuff too. I have been buying replacement nozzles from them for about a year.
These are extremely easy to hook up too. I mounted them inside the totes 3 to a side and spaced fairly evenly apart.
AEROPONICS DIY UPDATE FOR 2017
These really are great misting assemblies. Unfortunately they can be hard to find because the sellers keep changing their listings but they can be found on the Pro Water Parts site. Search for nozzles. Also they can be found here.
Currently both stores are selling the white assemblies which have lower gallons per hour than the black ones. You can swap out nozzles if you want higher GPH.
Over time I have reduced my timing from 1 on 5 off to 15-30 seconds on and 5 off and I would recommend the white or blue nozzles at this point.
I have found after a few years pump pressure begins to drop and that results in more water flow so I am using a smaller nozzle with lower GPA.
Running an accumulator could solve this problem and allow shorter on/off cycles and save wear and tear on your pump. Of course this makes for a more complicated build and I wanted a simple plug and play system to get you up and running.
I don’t run an accumulator set up at this time because my grow space is so limited but if you build this aeroponic system you might want to consider adding one or upgrading at some point. Here is a pic of a typical setup. Since your pump runs on 24V you can use a 24V solenoid and splice into your transformer if you don’t want to use a separate 12V power supply.
Push To Connect Fittings And Tubing
Everything in this build is 3/8″ tubing and fittings which makes set up easier. The pump I recommended has 1/4 fittings too but I wouldn’t use them, just stick with 3/8 outside diameter tubing. It is about $20 for a 1oo foot roll of LDPE tubing so its pretty cheap. Just make sure it is rated for at least 150 psi.
When you insert the tubing into the push to connect fittings make sure it goes all the way in. The teeth inside will grab the tubing before it is seated all the way in. Push on it and you should feel it hit a stop. If you don’t get it all the way in it may leak or even blow out of the fitting. There are several companies that make the fittings but John Guest Speedfit fittings are the best and the originator of push to connect fittings.
In my previous build I had 4 misters on the short end of the tote. I used double headed reptile misters and because they protrude out a couple of inches the area behind them was relatively dry. The misters on the opposite side didn’t penetrate the area that well either so I lost a couple of seedlings in the corners in my old system. This set up is a vast improvement with much better coverage and a lot more mist.
I used a tee connected to the bulkhead and ran a loop of misters. I like to use a closed loop system because it provides even pressure to all misting heads. This is how parks and golf courses get such even water distribution over large areas.
You can just come directly from the bulkhead without the tee and run them in a line if you want. You will need a 3/8 plug for the last misting head in the line.
Each tote has an independent supply line connected to the outside of the bulkhead. I used a 4 way cross for this or you could stack tees and do the same thing.
You can also run a single line that tees off to each tote. The last fitting in the line should be an elbow or a tee with a plug in it. If you are building only one tote just run your tubing straight into the bulkhead.
Below is a picture of my set up. I have a line from the pump going to an inline filter, a tee with a pressure gauge and then the cross. I used a stem elbow on top, connected that to a stem elbow on the middle tote’s bulkhead. The other 2 lines run to the left and right totes.
I have a 10 gallon mixing tub beneath the totes which drain into it with 3/4 inch tubing. Inside the tote is a 50 micron filter bag. Into this I inserted a piece of 3/4″ PVC pipe and a cap with a 3/8″ hole drilled in it. I did this because the tubing wants to curl upward. This way the tubing is straight and at the bottom of the mixing tub well below the water level.
Here is some wiring and my CT 1 short cycle timer. I have been using this timer for 2 years now and it has never skipped a beat. Space is extremely tight in this grow closet. In fact these 3 totes fit in with less than 1/8″ to spare. I measured carefully so I knew they would just fit. I have to tip the tote ends up to remove the lids. Fortunately that should only be necessary between grows. Plenty of mist inside these totes. There is even more when the lids are on. Some young White OG and Headbanger seedlings settling in to their new homes. I will be posting a grow journal on my DIY aeroponics system and the plants you see in these pictures.
You will need to use clean nutrients with your aeroponic system. If you are in to organic growing this system is not for you. Don’t use molasses or any organic based products or your system will clog.
There are many clean nutrient brands you can choose from. I have had good luck with Dutch Masters and am currently trying Advanced Nutrients Connoisseur A&B. It seems pretty clean and so far so good, but I don’t think I would want to use some of their additives. Some people really like Canna Aqua too.
Many nutrient manufacturers say their nutrients are suitable for hydroponics but remember that aeroponics is different and some are not really clean enough to use in your system.
You don’t want to use Heavy 16 in these systems even though they say you can use it in hydro. Also most of the Aptus line is not compatible.
RO water has all the minerals removed, and this means you will probably need to use a cal/mag supplement. Some nutes like Dutch Masters add this and some don’t because they assume it is in your water already. If you are growing an OG strain you will need to add supplemental cal/mag regardless of your base nutes. I like CaliMagic from General Hydro but there are others.
Finally you are going to need a TDS meter and pH pen. You need to monitor your pH and nutrient levels. Your plant’s roots are hanging in air and have no buffer. This is what makes aero so successful. Plants don’t need to forage because everything is right there. But it is a double edged sword because if things get too far out of whack things can go south in a hurry.
You will want to check your ppm and pH daily to avoid lock outs or other problems. I usually check mine at lights on and it takes very little time to do manually but you could install a nutrient monitor in your reservoir instead.
Your plants won’t need as much nutrient so never mix according to the label. To be safe I would start at 1/4 the recommended rate and work up from there. Most people tend to over fertilize and this is one case where less is more.
I hope this aeroponics tutorial has been helpful to you and inspired you to give high pressure aeroponics a try. If it has please like and share this post so others can learn from it too.