Aeroponics home unit first grow feedback


#1

Hi Friends,

Long time lurker, first time poster here. I have been researching aeropoinics for a few years now and recently built what i consider a primitive aero unit and started my first grow. I wanted to post it here for some feedback. I hope this thread serves as a place for people (me inculded) to learn how to improve their setups. I have started my first grow and wanted to share my progress so far. my goal is to build a fully automated aeroponic unit, or the more trendy term, “food computer.” I would like to have one setup that works for all plants, by just changing the nutrient recipe.

Below is a rough BOM of the hydraulic components

  • Seaflo pump - 160 psi diaphragm booster pump,
    • kicks on at roughly 80 psi and kicks off at 120 psi
  • Seaflo Accumulator tank - set to ~110 psi
    -Adjustable Pressure release valve - from McMaster set to 140 psi
  • 1 gallon reservoir tank - where i take water temperature and put nutrients
    • i am using GH flora series at the recommended hyrdo levels
  • 3/8 push to connect fittings and tubing
  • Dripworks low flow red misting nozzles
  • 12 VDC stainless solenoid valve, located close to the nozzle for precise control
    • i want to switch to DC but just haven’t yet

For the controls, i am using a particle photon. I pick this controller for the ease of use and in my opinion it serves this better than an ardunino would. The controller is pushing data to google sheets. The data its pushing is ambient temp and humidity (dht11), water reservoir temp, and nutrient chamber temp. I am manually taking PH and EC because I just haven’t put the time in to find a cheap reliable pair of sensors for this.

My first grow:
I ordered some Jalepeno seeds offline, and germinated them in four rapid rooters until they sprouted (about 7-10 days). I took removed two of them with surgical precision and the other two i left in the rooters, surrounded them with hydroton and placed them in the unit. One of the two i removed from the rooters died almost immediately, the other is doing just fine. I am using distilled water bought from the local store. It’s not ideal i know but its doing decent so far. I initially filled up the one gallon tank with 0.75 gal and the appropriate nutrients, I topped off the tank when it gets low, but do not add more nutrients. I am also running drain to waste. I do this about 5 times them i re-add nutrients when they get low (under 100 microS). I have re mixed nutes two times in those the last two weeks. Just in the last few days I have had roots poke through the netpots but i do not see any of the desired hairs on the roots just yet. I think this has to do with the temperature of the water/ nutrient chamber. It is hovering around 70-75 degrees. its operating at around 80-120 psi.

Questions:

  • is drain to waste really beneficial? I found that i am using a lot of water, just over 4 gallons in since the start
  • Does anyone recommend EC or PH sensors that are fully submersible and reliable long term?
  • when starting the system i have to purge the air to get the pressure to rise, are there valves for this? a check valve comes to mind?
  • is RO really worth the huge price and other difficult requirements? (pressurized inlet and drain tank)
  • i am misting 3 seconds on and 10 minutes off and seems like its doing just fine. should this change based on time of the day and/or ambient conditions?

I look forward to you guys tearing this apart in the spirit of constant of improvment of course.
Thanks,
James

here are some photos

IMG_0443

(upload://hP3eAll3ENWvIqxYz0xScB9Xjr.jpeg) IMG_0445 IMG_0444


#2

Hi, what a nice setup! Just wanted to confirm a few things. What is the flow rate of your nozzle, I did a quick search, is it 0.9 GPH @ 100 PSI with 50 Micron Droplet size? If that’s the case, refer to what @Atom said in the past, you want that maximum 1 mL Nutrient : 0.1 m3 Volume misting ratio. So I would assume you probably had supplied too much nutrient to your root system, thus no aero roots. Also, I don’t recommend directly spraying to your roots. I think if you can achieve this, drain-to-waste would make more sense eh. :smile:


#3

Awesome setup! Do you find that you have to clean algae off of anything (e.g. tank, plant tub)? What is the general cleaning/maintenance required?


#4

Hi, Thanks for your reply! those look like the stats for the red nozzles I am using. Its really hard to tell droplet size as you can imagine without precise tools, but the mist is almost invisible without direct light passing through it, which makes me think that I am close to that level.

I have followed what @atom has said on a number of posts. unfortunately i wasn’t registered so my reading time only reflects what i’ve done as a register user. I do have that post bookmarked in my research documents, but had some trouble making sense of it. Is it meant to dictate the spray time, or nutrient concentration? I have noticed in the last few days some browning at the tips of some of the roots, but all else looks fine on the plants. From what i have read that could mean I am suppling too much nutrients.

How could I indirectly mist the roots? like capture the sprayers in a cylinder that vents to the chamber, it would all be captured in the main chamber I imagine.
Another concern from not doing drain to waste is the solution going ‘stale’ over time, is this a valid concern? I wanted to implement a U-bend drainage system is a UV sterilization to kill everything, but I am unsure if this would work. thoughts?


#5

Hi, thanks for the reply. I have only been running this system 24/7 for maybe three weeks and haven’t considered cleaning the components just yet. I was planning on running a diluted hydrogen peroxide solution after this first grow, then dismantling all the components and giving them a good old fashioned cleaning.

In regard to the algae, i did notice in the first few days there were some suspect white cloud like floating particulates in the solution a few days after adding the nutes, but haven’t seen them since. All seems to be going well so for now i’ve turned a blind eye to it.


#6

From my experiment and understanding, the ratio implies the ideal floating nutrient droplet density within the root chamber. The effect of gravity on droplets that are 20 - 60 microns in size is not significant. The water droplets can float in air for a fairly long period of time. Thus you don’t want to over saturate your root chamber with too much water. You can control this by selecting nozzles with ultra-low flow rate, or through controlling the spray time. So for example, for a 0.1m3 sized root chamber, you only want 1ml of nutrient being spray every time.

For that 1mL : 0.1m3 ratio, refer to atom, you are close to the ideal droplet density. You can check your root chamber volume and figure out how much ml of nutrient mixture you need to spray, for the spray interval, I would say 3 min is a safe number.

For non-direct spray, I just meant that do not place your nozzle vertically and pointing directly to your roots because that will quickly build up to larger droplets (the whole thing then becomes a NFT setup). You want the fog/mist that comes out from your nozzle fully expand and occupy the inner space of your root chamber.


#7

Thanks for the quick and in-depth reply. My mist has no problem defying gravity which tells me that they are in the target range of size.

My initial pass had 10s on and 3 min off but found that i was getting drops on the bottom of the netpots. So i tuned it down to 3s on and 10 min off which has the chamber nice and moist and am not getting water droplets forming on the netpots. Unfortunately I don’t think my chamber is large enough to accommodate indirect spraying without spraying directly on to a wall.

I will have to take some measurements and run some flowrate calcs and dial in the timing to match. Any thoughts on the nutrient concentration. I have been using half the concentration of what the General Hydroponics Flora series recommends for hydro, is this still to strong if I am having the tips of some roots brown?


#8

Hi
The1ml /100L is related to full coverage and 5-80 micron droplet range. The mist should fade to a light haze between mist pulses. You should be able to see the floor of the chamber through the mist at all times. Brown root tips are usually caused by too little mist or an overly long pause duration. If you are using netpots and hydroton (or any media with gaps) check they are not allowing light and airflow to reach the roots, it doesnt take a lot to dessicate the delicate root tips. For initial experimentation i`d recommend starting with well rooted tomato cuttings which do very well in hpa, they have fast root growth and are not easy to kill :wink:


#9

Hi,

Thanks for reply. I have looked far and wide to find a decent way to start seeds in a HPA setup and that’s what led me to the rooter & hydroton setup. Is there a better way? I found that HPA is used alot for cloning, which in that case I could defineitly stick it in a foam plug and let it hang in the chamber. Is that what you mean when you say “well rooted?” Or do you mean a tomato plant from a different medium that is doing well? If the ladder how do you remove the debris from the root network so that the chamber isnt full of dirt?

So it seems like my 10m OF 3 sec ON isnt the optimal. I will adjust and report once i take the time to run the calcs on it. I just realized that the grow chamber i have is a light color (seems like a natural, injection molded PVC) and is keeping the inside of the chamber less than dark. I have seen people wrap their grow spots with that foil type insulation, seems like this is playing a part in the browning of my root tips. That is if its not; the nutrient concentration or spray timing.

Thank you all for your great insight. I will continue to iterate and make the best damn HPA system I can. Take care.


#10

Well rooted as in having plenty of roots from the stem :wink: Toms will happily root in a glass of water but if you do a lot of cloning its worth making a hp aerocloner. You can start seeds in it using small discs of coco mat that are misted from below. Once the seedling has anchored into the coco disc you can move it into the main system.

This tomato was started from seed in the same way. Note how the stem expands to fill the hole in the foam collar providing extra support.


#11

Wow, that second picture is really impressive. I definitely will start my seeds in the was you suggest for my next grow, thank you!

Are you indirectly spraying your roots? @Cyclony thoughtfully pointed out that if the spray is going directly on the root, vs having the roots capture it from the air, its essentially a NFT system. I am curious as to your thoughts on this,

Thanks again


#12

Here are some photos of the root system under my aero setup
Even though the trial failed later on due to bacteria and fungi infection, the roots turned out to be good.


#13

woah, those look great. What caused it the roots to do the ‘monkeys in a barrel’ type structure. I have seen many people say that the bushy type roots are desirable? Does it depend on the type of plant one is growing?

I really appreciate all the feedback so far.


#14

To be honest, I don’t really know. I’ll consult with a friend doing plant research at UofT to gain some insight and maybe have an answer for you. But I did notice that when I was growing letttuce, I would get a bushy root system, and this time I switched to spinach it lead to this type of root.


#15

Thanks, that awesome of you. I’d assume it doesnt matter as long as we’re able to get the small hairs on the roots.

I am still brainstorming ways to get indirect spray in a small enclosed chamber. Stay tuned.