Tropical Fish Forums

[sevendigitcake]

I am looking to put a 35 gallon sump under my 75 gallon tank, but the poroblem is my tank is not drilled and I don't want to drill it. Is there another way to have a sump without drilling my tank. I am willing to get the 35 gallon drilled so I can have an external water pump, to avoid heat issues but I don't want to get the main tank drilled? Should I just avoid a saump all together.

[Slimy]

You can use an overflow box. Hangs on the back of the tank and uses siphon to bring water to your sump.

http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=18358&Nty=1&Ntx=mode+matchallpartial&Ntk=All&N=2004&Ntt=overflow%20box&Np=1

It's not as convenient as using a drilled tank, but it's far less hassle than drilling a tank
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A Quarter Fathom Journal

[sevendigitcake]

so if I get the overflow box what would I use to bring the water to a sump? a tube lke you would use for a canister filter? And also how large does the return pump have to be, GPH wise?

[Slimy]

The connection is generally 1 inch, so much larger than canister tubing. You can use PVC, flexible tubing with pvc fittings or buy a fitting to convert from threated to barb for large (1") vinyl tubing. It's mostly dependent on your setup. Either way, you don't want anything to restrict the overflow down to the sump, so plan to stay with 1" diameter.

To be on the safe side you always want the overflow (from tank to sump) to have much more capacity then the return pump. How much you pump back is really up to you, just make sure it's less then the rating on the overflow box you choose.
It's basically just as if you had holes at the top of your tank. If you pump back 200gph, you'll overflow 200gph. If you pump back 1gph, you'll overflow 1gph, so as long as your overflow can handle your pump's maximum output it'll be fine.
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A Quarter Fathom Journal

[sevendigitcake]

Thanks, I Wish the rest of the internet was as informative and easy to understand as you