Will this work.

[scottwhitson]

I am going to add a sump to my 55 gallon reef. I will be using a HOB overflow. Currently I have a canister filter and my question is could I use the canister filter with the media removed except possibly carbon or phosban if needed for the return pump back to the display tank?? The rating on the canister filter is 340 GPH which should be about right for a 20-30 gallon sump correct?? Any thoughts if this would work or not.

[scottwhitson]

Anyone???

[Shagsbeard]

no... you can't. I thought about this too. A canister filter requires a closed system to maintain suction. If the seal is broken it will no longer pump correctly.

A return pump can be pretty cheap though... much less expensive than the canister filter.

340 gal/hour seems reasonable for a 55+20 system. Make sure your HOB overflow is rated much higher than this though. You have to have your return pump lower in rating than the drain of your overflow, otherwise you get a flood.

[scottwhitson]

Thanks shagsbeard but what do you mean by a closed system? I am not understanding. I am going to by an overflow that is an overkill for my current tank but can use it if I upgrade it will have two one inch drains also so if one gets plugged it will still work.

[amike5]

Take the head pressure going up to the tank off your flow from that filter and your left with barely any flow. Canister filter pumps aren't made for much head pressure. IMO, I do not believe this would be beneficial for you to do.

[scottwhitson]

Yeah but the pump is rated at 340 GPH and I only have about 3 feet of lift to the top of the tank. I guess I will have to try it and find out if no one else has.

[amike5]

3 feet of lift plus 1 foot for every elbow. My pump ends up with at least a 40% reduction of flow from head pressure.

[scottwhitson]

Thanks amike5 I might buy a pump just in case. Any suggestions for a pump around 300-400 GPH and it must be quiet.