Google’s kind of letting me down here.
Anyone have some ideas/theories on a very microgrow sized hydroponic system? Trying to keep it <9" (228mm) tall. Without an external reservoir.
Not tied into any method, media etc, but looking for options - have the bigger 3d printers, cad skills so I can make most things happen… But still coming up short on picking something that may work in limited space.
Are you talking 9" over all height or just the root container?
If its just the root container, then the next thing that limits you is the no external rez part.
Two systems come to mind - kratky method and hempy buckets. I have never tried kratky myself, but it sounds nasty to me just from reading about the setup. Still, there are lots of folks who swear by it.
I really like hempy buckets myself. I have used them to keep mothers alive for months under really bad conditions - too cold and almost no light. I also use them on every grow to sprout seeds to put in all my aeroponic setups. They are stupid easy and zero maintenance and low effort. Just have a container of your preferred nutes ready to water with when the bucket gets light. I highly recommend Jacks 321 for any hydro setups. I do NOT recommend anything organic at all. The nasty bugs just love that stuff in hydro.
I suppose you could do DWC too, but thats one of my least favorite hydro techniques unless you can keep the water cold - which is very hard to do if the bucket is inside the grow space with lights etc. Warm water grows nasty bugs really well. That forces you to use beneficial bacteria to fight it or bleach or H2O2, etc. None of that has ever worked for me with warm water.
Tell us more about your proposed setup.
Edit: simple plan for a hempy bucket. Take any container and punch several small holes aprox 1/4 of the way up from the bottom. Spread them out evenly around the bucket. Fill the bucket with perlite. Add your plant, seed, clone etc, then fill with PHed nute water until it starts running out the holes. When its time to water again, just fill till it starts to run out the holes and stop. Once a week to ten days, poor in extra nute water after it starts to run out the holes. Maybe 10%-20% extra. Thats to flush any built up salts from the perlite. You can use just plain PH water for the flush if you want., then add some PHed nute water.
Alternately, you can just let some extra nute water run out each time you water. Thats how I usually do it. Im too lazy to flush.
Trying to come up with a short cabinet options. Friend asked about a stealth systems a lot like mine (mine’s not stealthy). Where you’re working in 30" or less vertical.
Cabinet they’re working with is a cheap press-board pantry - inside dimensions 24x12x30". Loose 4" above for lights/HVAC, 9" below for hydro… Down to 17" vertical grow space which is challenging but workable.
Reservoir could be in there, but has to be within the space not outside. That 9" could fit up to 7.8g of water…
DWC is out - well mostly, you’d have to be a shallow water culture. To have airspace you’d be struggling.
Krotky I’d looked at. I was really thinking of entering the quarantine contest with a 16oz version myself.
Doing a 2 plant nft (PVC or gutter) came to mind. Each plant gets a pipe/gutter exclusive, sump under & recirculate it.
I was actually pondering reversed ebb and flow last night… pumps on for dry time pumps off let the area flood again. Seems inefficient though since pumps on sucking air more than off.
Very difficult to do active hydroponics with such a low height and no external reservoir.
Not saying impossible, but maybe a short long rubbermaid tub with holes in the top for net pots is your best option. Like the ones they use for under-bed storage. Lot of moving parts for such a small space though.
Passive hydro like hempy buckets might be your best bet. I use them exclusively myself.
Basically it just all needs to be enclosed within the typically upper/lower half. When I say no external reservoir that means outside of the cabinet. Smaller ones that fit within the space are fair game.
Reading up on hempy buckets - trying to wrap my head around the theory. I like inert media (bugs were/are my biggest pet peeve) but notice some are running hydroton so more reading required.
Hydroton will work, but it doesnt wick as far - vertically - or as fast as perlite - the individual pieces are much larger than perlite. Perlite also holds more water for any given volume, and therefore drys out slower, so waterings will be further apart. Perlite is also easier for seedlings to get started. With hydroton, you almost have to start seeds in a different medium.
The theory is simple. The bottom 1/4 of the container - below the holes you make - holds water. That water will wick up to the top of the container. All that perlite above the water level will then have a super thin layer of water - which makes for exceptional aeration potential. The thinner the layer of water, the faster it can achieve 100% DO. That means your roots above the water level always have the perfect ratio of air/O2 to water. The lower 1/4 of the container is your rez.
For that short a growing space, you might consider autos. Ive managed some good yields from autos - 250 gms per plant dry weight on average, and more from some plants - using scrog in a small space. My tent is only a tad over 2’x3’ and I got 3000 gms wet in around 90 days from three plants. More than 7 gms/day dry yield.
If you can insulate the root section from the plant section, it will help a lot as far as nasty stuff in the roots. Even a thin layer of almost anything would work. Especially if you can vent the root section to help keep it cool.
Starting in Rockwool or peat pellets is something I presumed would happen. Was thinking a slightly more active system than fully passive. So daily drip emitters watering or something similar and - then overflow to waste or recirc.
Neighbours seen my temp cabinet, wants a similar system - but stealthy. She’s a brown thumb so less hands on for her the better. So I’m playing with ideas on how to make it happen with the current all in one design I’m working on.
coco coir won’t require a reservoir
Also not very hands off for brown thumbs to manage…
Also then needs 2 reservoirs for feeding - nute + flush.
Eh, see what happens, 16oz solo cup sized - hempy bucket with real hydro action 
Simple Air lift for active, I’ll throw a lid on the resevoir if it works half decent.
Now that is cute! I Like it 
If you use perlite, you would not want the airlift going full time. Just every few days for a short time to re-fill the lower portion.
For hydroton you wold probably need to run it more often.
If you ran it full time for either one you would be over wetting the substrate which would actually lower the amount of 02 the roots get…
Yeah I was figuring few minutes before lights on and again early/mid afternoon. Holes are way to big for perlite.
Basically a hempy bucket in a 1L resevoir at the end of the day, with some automatic watering action.
Worth trying in the solo cup covid competition, nothing else to do, printing the base/resevoir right now.
Thanks for that, yeah DWC is my usual preference, trying to learn and try new things 
It’s simple as can be and pretty much maintenance free except res changes every week or two other than topping them off
Ugly but watertight 
5% over-extruded 0.4 layer height and 260° for PETG with no cooling… About the ugliest print I’ve done in a while, but it does hold water. That was the important part here.
Yeah I’m bored
Media basket done. Bit of sanding because again water tight print… Then flame polish to come…
Working on a quick and dirty enclosure for it. Some leftover 2020 extrusion and some dollar store picture frames for glass walls.
Already found an issue with my lift tube - not working as drawn, not enough standing water - I’ll try thinning its ID a bunch see if we can resolve it that way.
Redneck engineering and cad at its finest
2020 frame, quick coat of white eggshell paint on dollarstore glass picture frame glass. Pics through a badly tinted front panel of glass now I remember why I get other people to do that for me. Can’t even do a flat piece of glass decent.
Another cheap amazon led light coming to finish this off, semi pissed off - before I order says will arrive by tomorrow… Order it suddenly next week. Grrr.
Still pondering next size up version of this, or a different system altogether.
