I need some help on building my own sump using an old 10 gallon fish tank.. I have a 29 gallon FOWLR which I want to build a sump for using a 10 gallon tank. Could anyone point me to a website or give me some advice? I don't understand how I can get the water to go from my tank down to the sump without a pump of some kind or cutting a hole in my glass tank. If I use a pump it seems like it would be way to hard to keep the water level the same in the sump at all times.