I have a 29g biocube (thanks Scott) and I have a custom sump (thanks HoF). The question is now how to get the water from the tank to the sump? Should I drill the back or should I do an external overflow? I have an external on my 75g and the noise bothers the little lady, so another one isn't in my best interest. Anyone done any mods to their cube to get water to the sump? Oh yeah did I mention the tank is filled with water, rock, sand, and macro. I can always just drain the back compartment to drill.