Is the drain on the bottom of the tank, or on the back/side? I ask, because my frag and fuge tanks are drilled on the back and side, respectively. And I can tell you that IF the bubbles build up, and they will, they can block the drain and cause a flood. This invariably happens at 1am or so IME.
I use an aqualifter to suck the air out the top of the durso, by drilling a small hole in the cap, inserting an airline connector, and connecting airline tubing to the aqualifter intake. I run a tube from the output to the sump in case water gets in. It's also a way to get air/oxygenation into the system.