How big are the overflows ( 1", 3/4 ", etc). I have a 1" (600 gph
) and I need a Mag 9 to even out the flow. So you drain size matters.
Are you feeding flake? For my FW
, I wet my finger; dip it in the flakes then release it under the water. The flow from the powerheads drives the flakes to mid tank and below pretty quickly. For the SW
, I turn the pumps off when I feed (the FW
has no sump).