Problem is its the front left top corner pump. 1 Pump there, 1 Pump in Back Right top corner (opposing the front one) and one more in Back bottom left corner blowing across back of tank. They are all on a wavemaker (Lots of alternating flow so far, although I'm thinking of adding 1 more) The Maxijet 1200's where fine for quick fix and low cost, but I eventually want to try some other set-up.