I have a 75g tank and a 30g sump. My return pump broke so I used another pump I had but it is a larger pump. My overflow has 2 1" drains so I should be able to flow about 1200gph according to most calculators. The pump is a little giant 4-MDQX-SC. With the head height and plumbing I am guessing about 1100gph at best. Should be able to run full bore with the overflow, however I have the ball valve about halfway closed. I was baffled and then I thought perhaps the sump may be the limiting factor since the baffles are about an 1" apart. Could that be it? They are an over-under-over setup. Even at 1" though I would think that is more volume than 1" pipe? Or could it be air entering the drain lines and not letting enough water flow?
I am baffled.
I am baffled.
