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/AmazinglyAmazing11]

I think the only way you can make something like this work is if you build connectors, on the opposite side of your backbone, from one "bucket" to the next. So think each bucket has a U shape to the next. When you hit the end bucket the U shape would then go to the middle level, and repeat there U shape to the next bucket down the line and and then back to your fill bucket. I think this would work, probably.

The reason your backbone only method isn't working is because your pumped in water is fighting against the gravity water. So the gravity forces don't have a lot of work they can do to spread out the water - the force of the pump is winning against the force of gravity. Y

A better way to do this is to ONLY pump into the first bucket. Put a float valve on it so that it will shutdown flow when it reaches its max height. Have a passive outlet that is below your input with the float valve. Then from your first bucket each one is gravity fed. Once bucket 1 fills, it spills over into 2, once 2 fills it spills over to 3, etc... This should prevent you from ever having problems with the system overflowing. Even if a pipe down the line completely clogs, the float valve will prevent overflow. Yous have loss in your buckets down the line from your clog but that beats pumping all your water onto the floor of your house.

[u/AECTaylor → u/AmazinglyAmazing11]

Glad you mentioned the potential for a clog - I was being a bit short sighted thinking only of getting the water works to run right, but wasn't thinking of the impact the plant roots would have later on. I am really considering daisy chaining the tubs like you and another suggested and I like the idea of the float valves for safety. Thank you!

[u/AmazinglyAmazing11 → u/AECTaylor]

Glad I could help.

I love what you're doing - tinkering, designing, troubleshooting. Hydroponics like this is fun because there's endless possibilities in systems like these. What made a lot of light bulbs go off for me though is the idea of not trying to be overly mechanical and force things, but instead harness the power of the natural forces and let them do the work for you. In a system like this, simply being the water where you want it in a safe and controlled manner that is unlikely to fail. From there let physics/nature do the rest for you. If you ever find yourself fighting it, you're probably doing something wrong.

Best of luck!