For a 20 long SPS/clam dominated reef... How much flow should I have coming through a 15 gal sump (with cheato & skimmer) through a 1/2" seaswirl mounted back center? I will also have a Seio 620 directed from front corner.
Wazz has it nailed... I would have as much flow as possible without the velocity.... the seios are great because they disperse the flow... your tanks is small. you do not want to beat the corals with direct flow....
wide flow is good. focused direct flow is not good for them
You need very little flow through the sump itself. Really only enough to feed the skimmer. Most of your flow should come from closed loop/powerheads/etc. How much of that is only limited by your substrate.
