I have slowed my flow rate through the sump on my 465 gallon tank. I am not concerned about water circulation in the tank with 4x MP60s and 2x MP40s, but my tank is so much quieter with a slow flow, maybe 2x tank volume in an hour (guess). What are your opinions regarding slow flow through the sump vs high flow through the sump. Do you think skimmers work better or worse with a slow or med/high flow, or is the effect negligible?