where should i drill the bulkheads for sump.

[rustyspurs]

hi,
ive got my plans pretty much sorted for my plywood tank as far as sealing/glass etc.. goes, however im unsure on the best way to install the plumbing for the sump.
ive read up on loads of threads but cant seem to find an explanation of the differences between drilling bulkheads on the back of the tank as opposed to the bottom.
also i dont understand why people box the bulkheads off..
sorry for the idiot questions but i need to figure this out as i can drill anywhere now and want to get it right first time..
any all advice welcome

sorry meant to say, the tanks 6ft L by 3ft h by 2ft d, it sits on a 2ft stand and i plan to use 1 or 2 rubbermaids as the sump.

 

[Pharaoh]

The only real difference would be in risk of failure. If you have a leak, one on the bottom could drain the tank. You wouldn't drain nearly as much if they were on the back up high.

Other than that, it is pretty much aesthetics and ease of access.

 

[rustyspurs]

cool thanks, high on the back it is lol,
are the overflow boxs just to reduce noise/ expel air?

 

[jcardona1]

The box is for surface skimming basically. The bigger the box, the more surface area is skimmed.

 

[rustyspurs]

aha said the blind man, now i see.. thanks