Single Pump Aquaponics System Design

I use an architecture in my aquaponics setup that requires a single pump per fish tank used.  This minimizes electricity and vastly reduces the complexity of the control system.  The water is pumped to my sludge separator design (see blog for details) which is at the highest location in the system.  Gravity is then used to move the water from the separator to the grow beds and back to the fish tank.  Using more than one fish tank in the same system requires balancing the effluent water from the grow beds and this will be addressed in another article.

The schematic of the setup is shown below:

The fish tank is shown below:

 













The sludge separator is shown here.  The pipe on the right is the influence. The pipe protruding from the front is the overflow back to the fish tank (a safety measure).











Here the piping is shown from the grow beds (3/4") to the collector (2") which returns the cleaned effluent back to the fish tank.

Since I use flood and drain as my water distribution, I could technically just keep the water pump running. I use drains on the side of the grow beds.  This side draining is much less efficient than bottom draining and what happens is that the water slows down in draining as it gets to the bottom of the bed.  This causes an equilibrium to be reached if the water pump is left on all the time.  At equilibrium the water is about 1/3 depth in the grow beds at all times.  I alleviate this problem, and save electricity to boot, by putting my water pump on a timer that runs 30minutes on, 30minutes off continuously.  This means I only pump half the time. It also allows the grow bed to get flooded and drain once per on/off cycle.

I have not had trouble with the side draining, but it does take a little tuning of the bell siphon.  We will cover this siphon design on another article.