So I was having problems with my G6's. They would only run at half their flow. I cleaned them throully and still low flow. So I swapped them out for two FX6's. Needless to say I have great flow now. Between the MP40 and the two FX6's this tank is rocking. I think the higher flow is better for the mosses. I also add carbon for the first time. One thing that sucks is I had two inline heaters that I can't use because the FX6's tubing is too big. I think I'm going to make a inline chamber out of PVC and install a heater into that.