Return pump question

[Myka]

My tank is roughly the same size (90 with 12 or so gallons of sump and fuge), and I am using a Poseidon PS3 as a return. It is dead silent, but will raise temp of tank as previously mentioned. This pump produces about 700 gph at 4' head, and i'm even stealing about 100 gph from it for the fuge. This gives me a little under 6x turnover through the sump which is ideal. Most people recommend 3-10x turnover through the sump, but 5-7 is the majority. There is still oldschool thinkers out there that push for the 10-15x turnover which imo is silly because you risk microbubbles infiltrating the display tank which is no good at all.

If you're wanting more flow in the tank consider using your concept with a closed loop pump instead of the return. The way you have it now, even with a 1200 gph pump you will not get a huge amount of flow out of those 4 return lines.

Also be aware that using a SCWD reduces the pump's output by about 30%. Although much pricier, the Oceans Motions devices don't do that.

I will also suggest using 45s instead of 90s where possible.