I hope this is the right place to post this, and help would be appreciated.

I've have been working on a multi tower hydroponics system for the past couple of weeks. I'm currently trying to figure out how to get the pumped water, back into the water tank. However I'm having issues with the water overflowing in the return pipe, and not flowing into the tank(5 gallons).

Diagram of piping

Picture of return water into water tank The current pump is 1056 GPH, I realize it is too strong and I am looking for something with less GPH.

The return pipe has holes drilled into it, which the towers water return sit in. This is where the water overflows, because it is not going into the tank. I was hoping that the suction from the pump would be enough to force the water back into the tank, but I was wrong there.

Any suggestions, how can I have the water flow back into the original water tank?

I'm no expert so sorry for the amateur diagram.

Thank you


closed as off-topic by JMac, Kyle Kanos, stafusa, John Rennie, Jon Custer Sep 20 '18 at 22:41

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  • $\begingroup$ For clarification: the connection between the tower drains and the 2" collector pipe is just a loose fit? Not meant to be water-tight? $\endgroup$ – DJohnM Sep 19 '18 at 19:29
  • $\begingroup$ Are you sure you have the check valve installed facing the right way? $\endgroup$ – cms Sep 20 '18 at 2:59
  • $\begingroup$ @DjohnM correct, it is a loose fit. $\endgroup$ – Methos Sep 20 '18 at 17:16

Check valves only open if the pressure is lower on the outgoing (tank) side than the incoming (tower) side.


If your schematic is accurate, then the check valve is not opening because the water level in the tank is higher than the bottom of the towers. In other words the water pressure of height $H$ in the tank is holding the check valve shut. Make sure the water level in the tank is lower than the bottom of the towers.

  • $\begingroup$ I see thanks, I figured that would be a problem. The tank does contain more water than the return. I was thinking of adding a secondary pump on the return line to help push the water into the tank. $\endgroup$ – Methos Sep 20 '18 at 17:17
  • $\begingroup$ Or lower the sump pump so the water flows horizontally into the top of the tank, *above the surface of the water in the sump *, not into the bottom... $\endgroup$ – DJohnM Sep 20 '18 at 19:11

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