Proper Flow?


New member
I have a 150 gal DT w/ about a 40 gal sump. I have a closed loop w/ two 1.5" or 1" bulkhead intakes and 4 same size returns, plus 6 3/4" return pipes coming in from top. I cannot remember exactly what size they are. I just know I can screw a 1" threaded fitting in the inner threads of the bulkhead. So, I guess that would make it a 1" bulkhead. Anyway, I have a Hayward 3/4 hp pump hooked up to this closed loop. The problem is I am getting a lot of micro bubbles when the pump is on high. (about 3400 gph) I still get bubbles on low, but you can only tell they are there due to them collecting on the back foam textured wall. My real question is what is the recommended flow rate if I want to keep SPS? Right now I only have soft corals and a carpet anenome. What pump or pumps are recommended?

Also, what is the recommended flow rate for the return pump from the sump. I have two same size bulkheads for overflows as I do on the CL.




Owner of Canada Corals
Aim for 50X turnover for your closed loop if you want happy SPS.

The flow rate thru your sump should match how much your skimmer can process.

Detec AP-600 throughput is 133gallons per hr for example.


New member
That means that you are moving 50 times the volume of your tank through your closed loop, or some form of circulation. I have 20 times the volume of my tank in flow in the tank, using 3 Darts, and my SPS are very happy.