THE LOCATION: On top of a mountain in Southern Oregon.
THE CREW: Devin Richman, Kenton Price, Jackson McCormack, Troy Cromwell
THE GOAL: To create the most efficient grow set up possible with a limited budget combining the benefits of a climate-controlled greenhouse with the most efficient and cutting-edge hydroponic growing methods available for monster tomato plants!
DESIGNING A HYBRID AERO-FOG-SWC SYSTEM
This system irrigates each plant in three different ways, yet it’s blissfully simple. It’s essentially a modular re-circulating system which incorporates: shallow water culture (SWC) aeroponics misters and aeroponic foggers.
Each plant gets the VIP treatment, basking in a 20 gallon Rubbermaid container! Wow! There are 70 plant containers in total. They are all joined together via ¾” tubing. Nutrient solution is pumped from an underground 55 gallon reservoir with a 1546 gallon per hour pump to the middle of each container. Within each container there’s a large ¾” flexible PVC irrigation ring with 3 x 180° misting nozzles ready to rumble. When the misters are on, the container gets filled with small droplets of nutrient solution, the droplets that don’t get absorbed by the roots fall to fill the bottom of the containers. As the container fills past 2.5 gallons, the solution reaches an overflow tube, from here it returns through ¾” PVC pipe back to the main reservoir.
After running a few tests Devin adjusted the return pipe to the reservoir to make it a more direct return. The foggers are set to spray for almost 7 minutes on and off for 4 minutes. This timing is deliberately adjusted so that sometimes there is only fog, sometimes fog and sprinklers, and sometimes sprinklers half the time and fog half the time. The timers are set so that different watering techniques are activated at different times in different combinations. The logic is the plant won’t get too used to anything and it also allows the root zone to dry a little, encouraging the root hairs to go in search for food. This makes the roots very tenacious, white, and strong.
As soon as the solution returns back to the 55 gallon from the overflow the system kicks back on. The return takes almost 4 minutes. When spraying the roots, the solution comes from the 55 gal reservoir, and it takes just 7 minutes to empty the 55 gal. This is the maximum watering duration that Devin feels he can achieve without getting a bigger reservoir.
In the bottom of each container is a 4” air stone, these are connected to 4 x 750psi air compressors to infuse the 2.5 gallons of nutrient solution with oxygen rich bubbles. Sounds just like an interesting re-circulating system right? Well here is the secret to this high yielding system…
Each container has an aeroponic fogger floating just under the surface of the nutrient solution. Each fogger has three disks. These foggers are on a 5 minute on, 5 minute off cycle to create an extremely fine mist or ‘fog’ with a particle size of 3-5 microns! Such a fine fog of nutrient solution creates supercharged roots with an abundance of fine root hairs. These root hairs can take up water and nutrients at a rapid rate creating explosive plant growth. This technique of utilizing ultra sonic foggers to deliver a nutrient fog to the roots has been recently dubbed ‘Fogponics’, although officially it falls under the banner of aeroponic cultivation.
AEROPONIC FOGGERS
Aeroponic foggers come in various shapes and sizes but all utilize the same technology. They work by sending ultrasonic frequencies to ceramic disks which sit just below the surface of the water. These ultrasonic frequencies vibrate the disk which oscillates the water above creating an ultra fine fog. This fog has such a small particle size that it feels dry to the touch yet it can easily penetrate roots without totally saturating them.
CHALLENGES
1) Foggers
The main drawback of using most foggers with nutrient solutions is they can become clogged very quickly with nutrient precipitate. Even using foggers in hard water alone can cause a quick build up of lime scale, let alone adding mineral salts to the mix, so how does this extreme aeroponic system get around this?
Through trial and error and with some help from Ryan Clout at Sunflower Supply and the online garden forums, these crazy cats found a solution. Devin located a company online selling Teflon coated disks that are longer lasting and keep residues from building up on the disk surface. This drastically prolongs the life of the foggers reducing the need for constant cleaning and frequent replacements.
As mentioned previously, the foggers need to be just below the surface of the water in order to emit the ultra-fine fog. To enable the water level in the container to rise and fall while still allowing the fogger work it became clear that the fogger would have to float. So armed with a tiny budget and a trip to the dollar store, the floats for the foggers were created from play snorkels and net cups for only a dollar for each fogger!
2) Solution Temperature
While in operation, the foggers generate a significant amount of heat that gets soaked up into the nutrient solution. Even with the solution circulating from a large reservoir around all the containers, the temperature of the solution in the bottom of the containers was quickly rising to beyond 75°F. Ideally the nutrient solution should be around 65°F for optimal levels of dissolved oxygen and nutrient uptake. This was a tough nut to crack. The way forward was to cool the nutrient solution and, being and inventive bunch of growers, they decided to make their very own homemade water chiller.
Using an old freezer (2ftx2ftx4ft) as the cooling chamber the crew drilled two ¾” holes through the casing, one near the top and one near the bottom. The cooling mechanism was created by constructing a coil made from 25ft of aluminum tubing. This fitted perfectly into a five gallon bucket which had a drilled hole at the top and bottom. This allowed the ends of the coil to come through. Then, they fed a ½” hose into each of the holes in the freezer, used silicone to seal the holes, and connected them to the coil lines. After making sure the hose and coil were watertight, they used non-toxic propylene glycol antifreeze to fill the five gallon bucket and popped a lid on it.
This homemade chiller is located next to the underground 55 gallon reservoir with the upper ½” hose connected to a pump in the bottom of the reservoir and the lower hose draining the chilled solution back into to the reservoir. This constant flow of nutrient solution being pushed through the chiller created a constant nutrient solution temperature in the reservoir of 60°F, with the containers stabilizing at 70°F, keeping the heat emitted by the foggers under control.
3) Environment
Being in the heart of Southern Oregon, air temperature during summer is also an issue for this aeroponic set-up. The roots are particularly susceptible to extremes in temperature as there is no growing media to act as insulation. On a nice sunny day, an outside temperature of 75°F can easily create up to 100°F in the greenhouse and that’s with the 24 inch ventilation fan and both 24 inch passive shutter inlets open! To keep temperature down on hot days a 25,000 BTU air conditioner was incorporated. It also doubles up as a heater for those cold nights in winter.
SYSTEM ENHANCEMENT
The secret to the system is the hybridizing of SWC, aero-sprayers, and the ultra fine fog creating by the foggers. Studies in the late 90s by NASA have shown that solely using ultra sonic foggers to feed plant roots creates a disproportionate amount of root hair with significantly less lateral root growth, making ‘fogponics’ less suitable for prolonged plant growth – i.e. bringing plants to full maturity. By combining the two aeroponic techniques of fogging and misting upper root zone and utilizing SWC to supply water, dissolved oxygen and nutrients to the lower branching roots, they have achieved the best of both worlds.
One key aspect of this hybrid system that Devin is keen on maintaining is a high beneficial microbe count, particularly predatory nematodes, in the growing media and nutrient solution. The beneficial nematodes are an excellent predator of fungus and bacteria, which Devin is sure will help keep the system clean.
To provide a good home for the microbes to hang out and breed, they have come up with a media mix for the net pots of 5 parts Hydroton to 1 part ‘loose fill’ Sure To Grow. Devin and the crew feel that this mix provides them with the ideal surface area for the microbes to stay happy.
To inoculate the system with tons of beneficial microbes they brew their very own worm compost tea!
DEVIN’S WORM COMPOST TEA
Step 1: To 16 gallons of reverse osmosis water, add 1 fluid oz (28.5ml) of fulvic acid and 1 oz of brewers’ yeast (used for home brewing beer and wine).
Step 2: Add 2.1 fluid oz (60ml) of Humboldt Honey Hydro ES to provide food and energy for the microbes.
Step 3: Add 4 teaspoons (20ml) of Cutting Edge Solutions’ calcium carbonate, the microbes to love it!
Step 4: Take 15” x 23”brew craft fine screen mesh bag and add 2.5 pounds of worm castings.
Step 5: Add and air stone (attached to an air pump) to the mix.
Step 6: Steep the worm casting bag in to solution for 72 hours.
Step 7: Remove the bag, give it a few squeezes and let the solution brew for another 12 hours.
Step 8: Prepare the nutrient solution, Devin uses Cutting Edge 3 part formula.
Step 9: Add the 16 gallons of fresh worm tea to 300 gallons of nutrient solution.
Using this technique the crew manage to brew a full 16 gallons for $15! With this fresh brew of beneficial microbes Devin says you can’t add too much. They even spray the mix on the plants in vegetative growth stage which they have found works best neat or at a minimum dose of 1 part tea to 5 parts water.
Using a plant viable form of calcium carbonate really works wonders. Microbes like to have some kind of nutritional buffer, whether it’s a little bit of potassium or even phosphorus, they just need some kind of mineral to feed off. Devin noticed that his nematode population is 10-15% higher when he used calcium carbonate. He used Cutting Edge Solutions’ calcium carbonate – once you open it you really must use within eight weeks, otherwise it can get susceptible to mold.
Using this concentrated homemade worm-tea the growers find they only need to use ½ to ¾ strength nutrient solution! The main reason is that the worm-tea contains a huge population of predatory nematodes and protozoa (single celled organisms that are found across several kingdoms). They are non algal, and non fungal (such as amoebaes, ciliates, and flagellates) and are the number one predators to bacteria and fungi alike. These little worm-like parasites are nasty little buggers. They are heterotrophic which means they cannot produce their own food. Instead they hunt bacteria and fungi while remaining harmless to you and your plants. They locate and shred apart the fungal mycelia and bodies of bacterial organisms which then provide plant available nutrients and minerals to the root system. It’s a beautiful circle!
Freshly brewed, actively-aerated compost tea and compost tea brewing machines with ready-to-use brewing kits are also available from several companies.
We recommend you check out:
To complete the beneficial microbe mix, they add other beneficial liquid additives. These include Canna’s Cannazyme and Botanicare’s Aquashield. Also, check out Sub Culture B from General Hydroponics.
Every two weeks they change out the nutrient solution for a fresh batch. To empty the system all they need to do is open up three taps – this allows the solution to run out through pipe work onto an outdoor vegetable plot, putting even the ‘waste’ nutrient to good use. To fill the whole system they prepare a 300 gallon reservoir which pumps the fresh solution to each container.
Devin has extensive hydroponic experience with flood and drain tables, drain to waste systems, Deep Water Culture, aeroponics, soilless and soil yet finds this hybrid shallow water culture/aeroponic/fogponic system the most sanitary, easier to clean with the least amount of nutritional and pest problems.
To provide support for the plants they use tomato cages fitted into the exterior of the net pots. This offers great support and allows the branches to be trained out, which in turn enables the plant access to more light, better support, more growth and more fruit!!!!
The assemblage of all these high yielding methods with a few tweaks has provided Devin and his crew an affordable homemade system that that they can literally (and physically) grow trees in!
WHAT DO YOU THINK OF THIS
SYSTEM? ARE THESE GUYS DESTINED FOR GREATNESS OR WHAT?
Special thanks to Ryan at Sunflower Supplies (www.sunflowersupplies.com) for his help with the ultrasonic foggers!
This is incredible!! Its genius. Ive been looking all over the internet for aeroponic info and this has been the most informative. Im a relatively new gardener and i just built a small self contained misting system in my window sill for lettuce and spinach. I would love to know what brand of misters and fogger machine they are using and where to obtain some. Also, what is SWC?
GREAT article. I’d be willing to send a sample of our biodynamic inoculant Genesis Compound and mineral catalyst TONIC for experiment in making compost tea to anyone interested. You’ve never used anything like it! Keep it up…peace & light
This is such a great article. I just built my first hydroponics system this past winter and I’ve always wanted to branch out into aeroponics. Now fogponics!! Too much! Keep up the great work.
Awesome setup!
while there were a number of interesting concepts in this article, does no one see the the problems associated in this kind of setup or the omissions and contradictory info in the article.
I would love to hear any ones thoughts on the matter as this type of system does seem appealing as a concept. so please prove me wrong.
Just a couple of points off the top of my head:
1) introduction of any “sweet” nutes in the final stages are gonna clog those foggers past any usefulness. likewise any powder based supplements that don’t fully dissolve past a certain point.
2) root growth will make foggers useless. either by clogging or sinking them.
3) regulating ph over the life span (2 weeks) of the nute solution in the res’ is gonna be near impossible. any ph up or ph down added to maintain proper ph required or preferred for the particular period of the lifecycle of the plant will take hours to disperse equally and consistently throughout the system before one can get a relatively stable and consistent reading. not to mention the damage that undiluted base or acid will do to the roots of ones plants while it is making it’s way through the system before reaching equilibrium. so how’d they really do it? i’m imagining an over 316 gallon master-master res where the entire nute solution can be diverted for any and all adjustments until it is stable enough to reintroduce to the feeding system again.
3A) two weeks? what about fermentation of the nute solution. even chilled to a constant 65 degrees, my master res is almost useless after 5-6 days. ph is through the roof from my desired 5.6-6.0 (depending on its use in the growth cycle) and requires daily and increasing amounts of additives to return to the desired ph just long enough to complete watering.
4) any infestation or fungi on a single plant will infect all plants. instead of organically or otherwise low impact treatment of a single infected/infested plant, one would have to nuke the main res and all individual res’ with serious chems in order to save the crop.
4A) seriously. forget about using mosquito dunks or other low impact clogging biologicals in order to control fungus gnats, etc,
5) article states 70 containers, diagram shows 80. photo of greenhouse shows completely different configuration.
6) 4 air pumps for 70 containers with individual bubblers; equals 1 bubbler for each 17.5 containers???
7) container layout diagram is woefully incomplete. right side contains only feed pipes, left side contains only overflow/return and drain pipes. why bother printing it at all if you’re not planning on showing any reasonable resemblance to the real layout?
9) also math on the nute solution quantity is confusing.
2.5gal per container x 70 containers = 175gal + 55gal res = 230.
nute solution is stated at 300gal + 16gal of worm/compost tea. so is there really 86gal of solution circulating through 3/4″ pipe at any given time? because this should probably be mentioned as that is a lot of pipe.
10) FINAL NIT-PICK:
the point of article was touted as a Low Cost/ DIY solution to aeroponic growing. you might actually want to mention the cost or rough estimated cost of this kind of setup in the article itself.
Oh yeah. Kudos for telling amateur growers how to brew their own vermi/compost tea instead of promoting certain large black boxes commonly for sale and advertised in such magazines. it smacks of integrity.
The Extreme Aeroponics article caught my attention (July-August 2010 Urban Garden). What will be the kilowatt hours of electrical power needed for the chiller and pumps? Will this cost be covered by the ability of the described growing system to produce a high tomato fruit quality/yield? Let’s devise hydroponic growing systems that do not require electrical power.
It isn’t the mechanical system but biology that usually does in most hydroponic growing systems, and this applies here. A fruiting tomato plant will require a liter of water a day (during the daylight hours), more or less, depending on the plant fruit load and atmospheric demand. The aeroponic method of water supply will not be sufficient to maintain the tomato plant turgid with a heavy fruit load and under high atmospheric demand conditions. What is the provision for maintaining the constancy (water volume and elemental content) of the circulating nutrient solution? For biological control, beneficial organisms require a food source. If the food source is the bad guys, without them the good guys will die, but even a presence of the bad guys can do considerable damage, although being kept under some degree of biological control. You need total absence of the bad guys, period! This requires that the nutrient solution must be sterilized if it is to be recirculated.
The answer to the question, “are these guys destined for greatest? – the answer is no. The system may “work” in terms of supporting a growing tomato plant, but fruit yield and quality will probably be low, and the operating costs high. I would also suspect that the nutrient solution dispensing system will not be able to supply the tomato plant with its required water and essential elements since a tomato plant has high water and essential element requirements. If this system was being used for a low requirement plant, then it might work.
Everybody is different and should respect great d.i.y skills,and as mentioned the cost is possibly underestimated, as if the bits and bobs were obtained from a diy store be cheap. BUT its the professional way its setup that sets it apart from other expensive systems. So instead of paying a healthly 4 figure for a system to grow 80 plants. Theyve shown that if youve good diy skills you to could spend a few £-$ instead of a few thousand. dont knock it-great attempt.not everyone could do that or do it well.
Should be noted Electric mixing with water is no joke=could kill. So have or know a quailfied electrican or risk floods,shocks,fire,etc. Thats the only disadvantage of hydroponics and often overlooked by over zealous sales people who dont know the industry. To me hydro vs organic.is like the hare vs the tortoise. the end goal is the same. ;-}
Ryan here from SunflowerSupplies.com, this response to the comment above from FloraHydro…
I disagree with your assumption that the root growth will clog the foggers….first off he ha a huge 55 gallon drum being used in each site!!! Just massive..if you could grow enough roots to fill that enough the fog will still penetrate better than an aero sprayer, and he has both.
As for “Sweet” products clogging the fogger it depends on if you buy a fogger like mine “Aeromist Fogger” which has a teflon coated transducer preventing build-up. Not all are created equal! Infact many people are using this Aeromist and the Cutting Edge Solutions “SUGAREE” which is used throughout the life cycle of the plant and increasing in dosage in the last month.
Also you mention your reservoir is useless in 5-6 days….you should be able to maintain a clean reservoir for a months at a time..your ph can be easily controlled via a doser for under $200 as well.
Lastly you mentioned “mosquito dunks” PLEASE DONT USE THESE HARMFULL PRODUCTS ON THE PLANTS YOU EAT!
Organic methods such as Neem and fly traps can be used instead.
As to DEVIN AND THE MOUNTAIN TOP CREW…you guys are awesome, and showing people what can be done is a real eye opener! These Aeromist Foggers are in use from small cloners to now…..THIS!
Anyone needing these exact foggers used in this just email me
email@sunflowersupplies.com
Ryan Clout