I bought a Wet/Dry Sump Filter w/Skimmer last weekend. Installed it tonight and the pump bringing the water back to the tank pumps faster than the pre-filter sending the water into the sump. The skimmer side seems to work just fine. I've even installed a plastic ball valve that I could restrict the flow a bit but that doesn't work either. I can't seem to balance the two out. Is the pump too big for the system? It's a 10g sump and I have a surge 3500 water pump.