Just got the 400gal !!!

[shua]

this is what he is talking about. pic done by odd ball

 

[Egon]

^ yup, that's the ticket

 

[Reeftanker3295]

There's no check valves to fail and there's no spilling even when power is lost. Basically the overflow is behind the tank. Water will not drop below the overflow hight. Ever. There's also a syphon break so water wont be sucked out. It's a very good system and keeps most of the plumbing on the outside of the tank. No waisted tank space with large overflows and no visible plumbing. I even put my heaters in the sump, I like the clean look.

Sorry I thought you meant putting the drains on the bottom holes so that the water would have to empty out of the whole tank so stop draining. I agree with overflow boxes.