Overflow size

[tcp316]

I have a 70G cube display and a 50G sump in the basement that I am getting ready to set up. I am going to order an overflow from glass-holes.com and am unsure which size to get. Their kits jump from 700 gph to 1500gph. http://glass-holes.com/Complete-Overflow-Kits_c3.htm;jsessionid=700541271EAE0A81EECCC700037049C5.qscstrfrnt01
I have about a 15' vertical head loss plus a 20' horizontal run.
my pump will cover 22' head max.
My question is what size overflow do I need? I am confused.
Vicki

[bellis31]

The 700 would be fine but I would get the 1500 because with the 2 - 1 1/2 drains it adds some redundancy.

[tcp316]

I plan on putting in two returns as well. What do you mean by redundancy?

[demonnite57]

Meaning if one of the pipes gets clogged somehow you have another pipe that is still working so you won't have a flood.

[bellis31]

I plan on putting in two returns as well. What do you mean by redundancy?

2 Overflow pipes in case 1 gets clogged somehow, also the 1500 skims more surface area of the tank. 2- 3/4 returns would be fine.

[tcp316]

Thanks, I just ordered the 1500. They emailed me back as well and suggested the same thing. I was going to order the 1500 then I was second guessing myself and thought it may be too much.

[tcp316]

I had a durso on my old tank. Looking at these overflows, I don't think a durso would work. Hopefully they aren't too loud. I did order a lid for it so that may muffle the sound.

[bellis31]

I had a durso on my old tank. Looking at these overflows, I don't think a durso would work. Hopefully they aren't too loud. I did order a lid for it so that may muffle the sound.

The new boxes from these guys have a baffle inside the box, the new design is pretty quiet so long as your flow is a good free fall with no 90 elbows, use sweep 90's or 45's.

Best of luck to ya!