I am about to plumb my 65 gallon tank and wanted run a few questions by any plumbing gurus out there. I am going to run two seperate canister filters in two seperate closed loop systems through 4 holes in the bottom of my 48"X18"X18" tank. The guy at the reef shop suggested I use 1" bulkheads for the inlet holes and 3/4" bulkheads for the outlet holes. He didn't mention why and I forgot to ask while staring at all the beautiful corals. Anyway, anyone know why and if this is a good idea? When having the holes drilled, should I use what size is recommended from the bulkhead manufacturer recommends or just measure diameters? Again, this would be for two seperate closed loop systems for each canister that will have a Hydor inline heater and GLA inline diffuser on the outlet side of the canister. Does that sound feasable?