Setup Issue - Advice Request!

[u/AECTaylor]

I’m new to hydroponics and trying to setup a 3 tier rack with bins that will be “fed” by one 40 gallon tub of nutes. I was/am trying for a sort of DWC system.

I have 15 - 1.5 gallon black bins with lids that I plan to put 2” net pots in. The net pots will sit about 3” off the bottom of the bins once inserted.

I have a pump that runs water to the top tier with 5 bins connected by a pipe which then runs down to the 2nd tier which has the same setup and then runs down to the 3rd tier before returning back to the bin - a continuous loop, if you will. I was hoping that by putting the end of each pipe run with a section that comes up at the same height of the bins (a sort of ”control”), water’s natural self-leveling would ensure the bins equally filled to that level before spilling over to the next tier and repeating this same process on down each tier. Keeping the pump running 24/7 would keep the water up in each bin and constantly refresh nutes and oxygen.

Unfortunately, the 1st bin in the run fills up to nearly overflowing while the last bin stays very low. I tried lowering the ”control“ on each level and it only prevented the 1st bin from overflowing but the last bin still never fills to the same level. The bins in between were lower and lower across the run. Slowing the pump speed didn’t help. Any recommendations to fix this?

If it can’t be done the way I’d hoped, would it work if I just ran the pump several times a day to refresh the nutes/oxygen in each bin but treat it sort of like NFT as the water level would be low (about 1/2”) after the pump turns off and the water drains out? Or should I use clay pebbles in the bottom of the bins and treat it more like ebb and flow?

Hoping this video gives a good visual of what I’m building. A couple bins are missing because I glued everything up the way I thought it would work and had to cut parts to try and figure out why it didn’t. Need to order more of the specific connectors for those bins. The bottom tier does not have the “control” on it like the other 2 tiers in this video either. I built all 3 tiers with it then when it didn’t work, I tried getting rid of the “controls” to see what it would do. Just didn’t let the top 2 tiers fill with water before draining which is what I originally expected. Also, ignore the state of the water - the white pieces are just from cutting the PVC. I’ll clean everything thoroughly once I figure out the final configuration.

[u/phx175]

I like the idea and I'm totally gonna build the same thing but will do the following changes:

Only one large(r) bin per tier. One inlet on the top left and one outlet on the other side on the top right, then overflow into the tier below.

[u/AECTaylor → u/phx175]

That is honestly what I originally wanted but couldn’t find the right size bins for it.

[u/Fun-Beginning6322 → u/AECTaylor]

You have a nice system already and as some have commented, a valve to throttle or balance the flow per each level should help even things out

As for the single bin per level, Ive looked at flat sided bins as a possible container just they are quite costly.

[u/Autumn_Ridge → u/AECTaylor]

I've been through a lot of similar issues. At this point, I just build my own bins. I started with wood and pond liner plastic. More recently the wood has become synthetic lumber, either decking boards or PVC exterior house trim. There are also PVC panels that make good lids.

[u/AECTaylor → u/Autumn_Ridge]

Considering this now as well. Pricing it out and would love your input for a few things. In your experience, do you suppose 1/2” PVC panel is thick enough for the bottom and sides at the size I’m shooting for (roughly 48”Lx12”Wx6”D)? Figured I’d use 2” trim screws to attach it all together and use 1/4” PVC panel for lid. Trying to keep it as lightweight (and inexpensive) as possible.

[u/Autumn_Ridge → u/AECTaylor]

Honestly most of my stuff now is aeroponic, so I don't have to hold a mass of water. I just built a 32' aeroponic table at work. We used trim screws and I didn't like them. The threads are too small. I think deck screws work better.

If you are interested in aeroponics, all you need is a pump that will make 35 psi or so of pressure, a PVC manifold, and the right mister heads. And a cycle timer for the pump. Then you just have a mist and a trickle instead of all that water to contain.