Number of Overflows on a 55 Gal?

[jdevlan]

I am preparing to drill my 55 gallon for a 20 gallon sump. I am considering two different overflow options: One center overflow or two corner overflows.

Here are my questions:

Would two corner overflows be overkill on a 55 gallon?

If I do one center overflow, how big should I drill my bulkhead holes (for overflow? for return?)

If I do two corner overflows, same question (overflow? return?).

I am considereing buying my overflow(s) from wetdryfilter.com (http://www.wetdryfilter.com). Are there any other options?

As always, thanks for your input in advance!

[der_wille_zur_macht]

First things first - how much flow do you want through the sump? Most 55g reef ready tanks come with a single 1" overflow, which gives you a max of about 650 gph.

With a 20g sump, I wouldn't want much more than 1100 - 1200 gph through it. So, if you go with two overflows, use a 1" hole in each. If you stick with one, a single 1.25" hole will be able to handle that much flow.

I wouldn't spend money on an overflow - all it really consists of is a two- or three- sided box with a pipe inside it. You can make one yourself for a few bucks of parts.

[bonesnreb]

i use 2 over flows on my 55g

[jdevlan]

Originally posted by der_wille_zur_macht
I wouldn't spend money on an overflow - all it really consists of is a two- or three- sided box with a pipe inside it. You can make one yourself for a few bucks of parts.

Can you point me to any info online on how to build your own overflow box? I think I could figure out how to bend acrylic, but how do you build the slots at the top of the box?