Properly Sizing Aeroponics System

#1

I just getting my feet wet in growing and starting to design my first system completely from scratch. I was planning on doing a HPA system and using the hypro AFD series nozzles recommended by @Atom . But I am not sure how to calculate the number of nozzles per plan I need for proper coverage. Also sizing of the reservoir tank, which I would guess is directly related to the number of nozzles used. Any other general advise for a complete noob is greatly appreciated.

#2

The number of nozzles wil depend on the chamber shape, size and volume, the mist pattern of the nozzle and where they are located :wink: As a guide, an upward firing hypro in a 15-16" deep chamber will cover a 12" x 12" to 15" x 15" area.

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#3

Also you can follow the @Atom first steps recommendation: That is buy some nozzles and try it. I recommend starts with hollow and full cone and try with different flowrates (0.2 to 1 GPH… ). Another thing yo consider it’s the pressure… I recommend to try with lower pressures (30 to 50 psi) and the increment to observe the effect of low and high pressures.

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#4

Is it possible to fill the chamber from the side. Meaning that the hypro would be horizontal.

#5

You could use all your imagination locating your Afd and you will have a beautiful hollow cone pattern. Another important thing it’s the long of the mist @Atom knows very well the diameter of the cone at each distance (1m long… 2 m long…) Remember: you can order the nozzle with or without Anti drip.

#6

You can do that but you have to be mindful of the mist pattern and obstacles. Its best to visualise the chamber fully populated with plants and mature root systems. If a nozzle becomes encroached you`ll lose its contribution to the coverage.

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#7

Just starting up. I have a 43" x 43" x15" deep 100 gallon chamber. Based on Atom’s recommendation I’m using Hypo AFD0.7-80 nozzles at 75-100psi. How many nozzles should I use and at what spacing? What firing time and interval would you recommend? Any help is greatly appreciated.

#8

A lot depends on the planting layout and plant type but you`d get ample coverage with 9 upward firing hypros arranged in a 3 x 3 matrix, a UF hypro mounted 3" above the floor will cover a 15" x 15" area upto 18" high fairly comfortably. This nozzle arrangement would work for a 4 row x 4 site planting layout for larger plants or (at a push) a 7 row x 7 site planting layout for small, compact plants.
The misting duration should always be as short as practical but typically not more than 2 seconds.That assumes the system is equipped with an accumulator and solenoids, not just a pump :wink:
The pause duration will be dependant on the growth stage, crop type, light intensity, etc. The day and night mist timing will also be different, less mist is needed at night.

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#9

Thanks Atom… The layout is 4 x 4 on 12 inch centers. I have several questions. Do you consult? My email address is db@hcdcs.com.

#10

I’m totally agree @Atom. I just want to add that you can try with vertical aeroponics and discover the challenges and advantages that it has. I’m a fan of vertical designs and you can create different geometries. Take the next in mind… An AFD HYPRO firing vertical and downwardly it’s capable to make a beautifull hollow cone of 40 cm long at a 35 cm max. diameter and an effective mist of 1 meter long. With this in mind the use of an AFD could be enchaced if use an appropriate geometry for grow up. Finally it’s all about experimentation try an hypotesis or an idea and make it happen that’s the only way to create expertise in the field. The best wishes for all your prototypes: I will wait to see your advances.

#11

The 4 x 4 layout is ideal. Looks like the corner nozzles will be about 12.5" in from the sides (6.5" to corner plant sites). I guess the tote walls taper down to the bottom so dont forget to account for the difference or the nozzles will be in the wrong place.
The only consulting i do is with swmbo :wink:

#12

Atom, we are a new grower of medical cannabis in Oklahoma. Medical cannabis was recently approved in the State, but few growers, if any, are interested in serving the real medical need. The law that was passed allows the physician total subjectivity in determining medical need and is commonly referred to as “recreation light”. Basically, anyone who wants a medical card you can get one. As such, most growers seem to be interested in producing products that are more associated with the recreational market and most dispensary employees lack the knowledge to help patients determine which product to use to treat their legitimate medical need. We started this business to correct his deficiency and to serve the true medical market. We chose aeroponics as the grow method that would allow us to produce the cleanest most consistent product. I have a background in the technical side of the dialysis field with extensive knowledge of water treatment systems. I have hydro grow experience from decades ago, but aero is new to me. I built a tote sized system to prove the concept and it has performed well. We will be scaling up with the large chambers mentioned previously with each of four rooms having 48 chambers. The chambers will be on two levels in four rows of 12. The system I am designing will be firing 432 nozzles at a time and will be draining to waste. If my math is correct the total volume will be .1368 gallon per second at 100psi. I plan on plumbing the system with 1/2" pvc. Some of my main mechanical questions are the placement and number of solenoid valves and accumulators. Some of my main growing questions are nutrient levels and firing durations/intervals. I understand that a lot of this will be trial and error. Given the nature of what I am attempting I am trying to gather as much information as possible to minimize the errors.

#13

I believe drain to waste is ultimately… wasteful. For a given mist the majority of the water droplets will never touch the roots. My current aeroponic system is recirculating 40L (~10 gallons) of nutrients per week, I’m using General Hydroponic’s Flora series and use the given feeding schedule as a starting point. It’s very difficult to know how well their feeding schedule fits an aeroponic system, however the more water needed the more nutrients you will use. Drain to waste will cost more to run but less to initially setup.

#14

Bottled nutrients have a mark up of 1000% or more, the typical cost for an EC 1.5 nutrient solution is a penny a gallon. Given the small amount used and rarely needing to go above EC 1, the nutrient cost is almost not worth worrying about. From an environmental point of view its a good idea to have a seperate system such as a flood and drain that can utilise the small amount of runoff from the aeroponic system. The “waste” will consist of mainly water and be relatively clean because its only been run once. Recirculated nutrients in comparison to the runoff would be far less clean and have an unknown elemental makeup. My personal opinion on using recirculating nutrients in hpa is akin to buying a ferrari and deciding to run it on kerosene (recirc) instead of high octane fuel (dtw) :wink:
I get a litre or two of runoff a day from my outdoor chambers which supplements a 12 bucket flood and drain system, it barely makes a dent. Roots grow rapidly in aero, it doesnt take long to fill space. If you need to conserve nutrients you could make a small chamber to get seedlings upto a good size before transferring them into a larger chamber. The downside is its much easier to overmist in a small chamber than a large one.

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#15

I think overall system design makes a difference on the direction you choose. My grow space is indoors and totally sealed in order to have totally control over temperature, humidity and CO2 levels. If you really want to crank up your plants you need to have control over the environment. The grow method itself only gets you so far.

#16

Its easier to control the indoor environment, free light is the trade off. I run drain to waste indoors too, it generates less run off because there are fewer environmental variables to affect the system…like clouds one minute and full sun the next :wink:
Environment should always be at the top of the list, optimising the nutrient side should be close behind. Recirculating is more work than drain to waste, checking and adjusting ph, ec, topups and eventually having to change it out. I prefer to mix the nutrient, fill the accumulator and wait for it to empty which can take anything from 2 days to a fortnight. The last drop of nutrient is the same as the first so i dont have to wonder what the plants are being fed. Nothing comes back from the root chambers so i dont have to worry about opportunistic pathogens taking up residence in the system and causing issues. To my mind, drain to waste has a lot going for it :wink:
If you are running the 10 gallon reservoir for a week and then switching it out, you could run 1.42gal per day drain to waste, gaining all the benefits, and use the same amount.

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#17

Between my AC and dehumidifier I’m pulling almost 2 gallons of water out of the air per day and nearly all of that water is coming directly from the transpiring plants (grow room is a large sealed container). There are five cannabis plants that range from 6" to 15" in height which are currently still in vegetative stage and get 18 hours of light per day. I was misting for 2.8 seconds every 4 minutes and then decreased the interval to every 3 minutes and the plants seemed to be happier. The design of the system has a huge impact on its operation and at the end of the day the plants are the boss, listen to them, keep them happy and all will be well.

If you look at people growing with dwc systems it’s just amazing at the results they are getting and the roots are swimming in water.

My goal is to understand the amount of consumables it takes for a given harvest. I’m tracking all electric, water, nutrients and CO2 usage and trying to automate as much as possible to reduce overall effort.

#18

If you run the mist 24/7 you`ll see it reflected in the ac / dehuey runoff. Assuming the condensate is solely from transpiration is quite a stretch :wink: You would get a more accurate picture by comparing the amount of liquid going into the chamber and the amount coming out. Its very easy to do if you test the real flowrate of the nozzles in situ so it includes the system losses. Run drain to waste and catch/measure all the runoff. A recirculating reservoir will have some evaporative loss. there are no evaporative losses from a sealed and pressurised accumulator if it is used as a dtw reservoir. I find your stance on drain to waste nutrients very odd when you are spending a small fortune running a sealed room with ac and co2 for 5 plants :wink:

Its worth mentioning that transpiration is not indicative of optimum growth. For example, high temperatures and low humidity will cause an increase in the transpiration rate as the plants attempt to keep themselves cool. With drain to waste you`ll see this as a sharp increase in the runoff ppm which signals the plants have stopped actively taking up nutrients, aka, slowed or stopped actively growing. With a recirculating reservoir, it may take a days for a ppm change to show up due to the large volume, With dtw you can see it almost immediately in the small run off container. i have dual probe tds meters installed on all my chambers to monitor in/out ppm difference. http://hmdigital.com/product/dm-2/

#19

I am just getting started, have a proof-of-concept system running, and realizing that the root chamber volume is a big space hog if the roots are all forming 15" long, 12" diameter cones, and the nozzles all fire in cones, since if you are packing your plants in, as closely as you can, you need to add extra depth for the nozzles to spray into open space.

I would like to go with a more vertical root chamber with nozzles either firing from top and bottom or from the sides and near the back wall of the chamber to maximize distance before the spray hits roots/walls. Going upwards seems like a logical improvement, and keeping the planting surface flat reduces lighting costs too. Has anyone made a tall and wide but shallow depth vertical HPA system? If so, what was your experience, and am I overlooking different issues?

Also, this system setup seems better suited to a fan style misting nozzle. Has anyone found fan style HPA nozzles? I want to run DTW, and the fan style nozzles I have found look like they are better suited to low pressure aero, and would use too much water.

#20

The mosr efficient shape for a vertical hpa chamber is a cylinder. Second would be a vertical wall with a deep cavity planted on both sides. Flat fan hydraulic nozzles usually have a coarse spray, whether they are the slotted or the deflection type. Flat fan AA nozzles would fit the bill but they`re not cheap…