1200GPH overflow on 90g?

[SeriousDude5]

I was wondering if (1200GPH Overflow kit)
Aquarium Overflow Box 1200GPH and video viewing - eBay (item 280461803144 end time Feb-01-11 12:28:36 PST)

Paired with a Mag-9 pump would be sufficiant for my 90gallon tank. Also is this an advisable setup? My sump shall be a 30g long.

 

[mr_X]

no. it's more than you need, first of all. secondly, the overflow will probably lose siphon with the smaller pump (i'm assuming you mean mag 9.5), which after head loss is going to be somewhere around 700-800 gph.
you need to have a pump that matches your flow rate on your HOB. otherwise after a while, you'll see a little air bubble in the J tube, then a larger bubble...then one day the overflow loses siphon (and the pump is still running), and that spells a wet floor and unhappy fishies.
i would use a 600gph overflow and a 700-800gph pump and choke the pump back until it's perfect for the overflow.

 

[neilanh]

or use a non-siphon overflow.

 

[mr_X]

oops...are you drilling the tank? i'm sorry, i just assumed you were purchasing a HOB unit, and not drilling. if you are planning on drilling the tank and using one of those glass holes type overflows, then you can go as large as you want. no matter how big, it's up to your return pump to dictate how much water goes down and back up.
sorry for assuming!

 

[SeriousDude5]

Yes, I will be getting the tank drilled, thanks for the update! Can't wait to get this tank started, upgrade from a 22biocube!