Hydro vs Aero system, thought and questions


Hi everyone. This is my first post on the forum, I apologize in advance for any english mistakes, and thank you for reading me.

I wanted to build a few « research » growth chambers to answer questions about hydro and aeroponics (but mostly HPA aeroponics). My first chamber is quite simple and answer a question already assessed by many other people : in a controlled environnement, what grows better between hydroponics and HPA aeroponics. This system also serve the purpose of starting somewhere with a simple enough system before assessing other problematics.

For this first system, I operate in a growth tent with LEDs, camera, sensors, and I will soon begin working on the coding part of both the raspberry pie and arduino to get control over the air (CO2, T°, Humidity) and the water (T°, pH, EC) and time control over the different pump. I wont go into details about the code, as I don’t even have ordered all the sensors yet :slightly_smiling_face:

But before starting everything, I had a few questions. I red almost everything on this forum, but there is so much informations, it is a bit overwhelming when starting, so I thought maybe some of you would have advices as for my current questions :

  1. My system is in close loop : I use reverse osmosis on tap water, and add it in a reservoir ( 100L, 37gal). Then sensors mesure pH and EC and add a nutrient solution and pHup or pHdown accordingly to get to the desire value. this solution is then pump in either the hydroponic system, or the aeroponic system. Droplet then go back to the reservoir.
    1. dropplet coming back in the reservoir will change pH and EC of the wate, but the sensors will detect it and modify it accordingly. I understand that the nutrient will not all be equally absorb by the root, even more in the two different system, and EC might not indicate the lack of a nutriment in particular or the excess of another. first question : how much time do you think I can keep 37gal of purified water, continuously alimented by a nutritive solution with pH ajusted, before having to change it entirely ?(of course, if nobody have an answer, I will answer it by running the system and measure when the plants begin to decay and which system do so first)
    2. As I only want one variable in my system so to compare hydroponic and aeroponic, The nutrient solution is the same for both, I understand from atom post that I should decrease nutrient concentration for aeroponic, I didn’t understand though if this will lead to sickness for my aeroponic plants or just waste of nutrient ?
  2. I will grow different crop in my system : something fruity like strawberry, something classic like basil, something that usually grow underground like radish. But I only have one nutrient solution for all of them, I know I should have one for each of them. Do you think if I use one nutrient solution that is said to be « all purpose » this will result in lack of taste, poor yield… or that it will lead to the death of some plant or no fruit at all for the strawberries ?
    If you provide answers for those questions, it will be valuable insight, then again, if not, I will assess the damage when running it myself.

But I have questions that will be really helpfull to get answer from on the aeroponic part of the design :
3. to my understanding, a water pomp should lead the water in a booster pump (such as the aquatec 8800) then to a pressure switch then to a solenoid and then to nozzle. Questions about that :
1. If I add an accumulator tank of 2 gallons, would that mean that the booster pump will work one time to put in the tank the water at 80-100psi and then shut off until this one is empty (resulting in something like a whole night without the pump running, I am asking for noise purposes)?
2. I don’t understand how much solenoid I have to add ? why more than one ?
3. my growth chamber is 60x40x22cm (23x16x9inch), and there is 11 plants. Will the hypro nozzle advised by atom will be a good fit ?
4. I red a post by webb.peter where he wanst happy about his solenoids, is there bad and good solenoid ? I also found that webb.peter is using a fairly less expensive booster pump than the aquatec 8800, does it work the same for such a small growth chamber ?

here are some pictures (It’s only a start, I began building yesterday)

I am sorry for all those questions, especially that i feel some are redundant with other thread on the forum, but even by reading the answers I still have those in my mind. Thank you very much for reading me and for those who would have insight or answer or questions about this small project. I hope this will give data interesting to some of you. If not this is the first project (that will take a bit of time considering the code needed, and that I am a biologist and not a coder, hopefully the MVP brain will help me a lot to get started) and will lead to more small farms in quite the same shape, trying to answer different problematic, each time by moving only one variable :
- I want to do a vertical design of a specific crop like cherry tomatoes, each row will be nourish with a different nutrient solution to assess the best recipe (and then change to another crop)

  • I want to work on the different stress and the timing of those on plants to improve taste
  • I want to mimick foreign soil and air condition to grow crop that supposely only grow in this location
  • I want to grow mushrooms and see if there is a way to make a commensal communication between hydroponic mushroom and aeroponic plants
  • etc. (maybe not all are good ideas, but all seems fun to me :smile: )

Thank you very much


200mm isnt a lot of depth for hpa, id suggest using 400mm for hypros.


Thank you very much atom for the insight, it’s true you told in other post it was quite small under 400 mm. i’ll buy a other bucket and surperpose those. Do you think using the same nutrient solution for both hydro and aero will result in failure of the aero ? Or just less good result ?


Also could i have an advice on where to put the nozzle ? I was thinking four on the bottom aiming at the roots and two on each side of the buckets. To not put to much water in the system, i was thinking alternating the ones on the bottom and the ones the side, so four nozzle at the time, all roots covered, but alternating the source position so they gain length and width


Two upward firing hypro`s should be enough for a 60cm x 40cm x 40cm deep chamber. I personally wouldnt use 11 plant sites in a chamber that size. My latest chamber is 80cm x 80cm with 9 planting sites (3 rows of 3). I prefer to run aero drain to waste, i use the small amount of runoff to topup a hydroponic flood and drain system.


Mm that’s interesting, I could use the drain to go onto another hydro project or go trough a RO to balance nutrient before adding more and equilibriate pH. but i think as a first project i want to test how much time the plants can live in a closed environnement with 100 gallon of water alimented by nutriment. Thank you for the advice on the nozzles, i’m going to double the chamber size and only grow 8 plant with 2 nozzle. I’ll let you know how it goes in a couple of week :slight_smile: time to grow