Drilling holes for 27 gallon rimless

[Lambert58]

Have a 27 gallon rimless cube for daughters room. I want to drill the back for a ten gallon sump/refugium underneath. I need advice as to the size holes for overflow/return(s), (1 or 2)? Along with placement i.e.how far down from upper rim?

[Twin Reefs]

I'm considering drilling holes for my upcoming tank project too. I understand the drain hole should be bigger than the return line hole. Given that you have a small tank, I would think a 1 inch drain and 3/4 inch return should be fine.....but ou better wait and see what more experienced guys have to say.

[Madmak]

Will you be making a small overflow box? If so, the top of this determines your water level and the height of the drain holes isn't too critical. A Bean Animal drain is quiet and safe, and easy to do, just 3 holes. I would think that 3/4" drains and 1/2" returns would be ok, upsizing wouldn't hurt either. Keep your return(s) high and you can avoid using a check valve. Buy your bulkheads before drilling, they all seem to require a slightly different size hole...

Here are a couple pics.

http://img.tapatalk.com/d/13/02/26/ataruzu7.jpg

http://img.tapatalk.com/d/13/02/26/atytesup.jpg

[Lambert58]

Wow, thank you! Was going to buy some kits from glass-holes, but wasn't sure how far up or down to put them.

[Lambert58]

Was going to put the 1 inch drain in the center with a surrounding toothed overflow box and two 1/2 inch returns in each corner to try to stimulate more flow.

[peligro]

I just had my nano drilled 2 week's ago. Two 3/4" returns. One 2" overflow. http://img.tapatalk.com/d/13/02/26/yjeru2as.jpg

Optimus G