pump choice for closed loop on 20gal

[oddiseus]

I am setting up a 20 gal and I want to add a closed loop to the back with a scwd. The back of the tank will be drilled, and all parts external. I have seen another tank with a closed loop that is externally plumbed, they used a mag 5. Two questions: Even thought this pump is a submersible pump would it be ok out of water like that? Is this a bad idea? I have also read about leaking issues from this pump. Would this be overkill to use a mag 5 on a 20 gal. My sump is also using a mag 5 to pump 3 feet back into the tank. So about 300 gph roughly from sump alone. I am new to nano's and I don't want to really blow it the first time around. Any suggestions on how to go about doint this will be great appreciated.

-Odd

[Cody Ray]

The mag drives have a gasket (spelling) between the screws and the impeller casing so they SHOULDN'T leak. My guess is that the people that were having leaking issues had pinched the gasket between the 2 halves which lead to leaking. If set up properly they shouldn't leak. I would recommend checking out a pool store for jacuzzi intake covers, they work very well for closed loop intakes.

[AIMFish]

I was interested to see what size pump others would recommend. Does this means that most aren't doing a closed loop on a tank that small? I'm not sure about the mag 5 being to much but you mentioned using a scwd and that would reduce flow a little. You could also put a valve on your output so you could cut it back if needed, or use a bunch of elbows! :rolleyes: ;) :p

[Paladin]

I have a closed-loop in my 29g where I use a Pan World 50px-x that puts out more than twice the flow of the Mag 5, and the pump goes through an OM Squirt, which doesn't reduce the flow like the SCWD. And I also have a Mag 7 in my sump for my return. So, no, a Mag 5 isn't overkill. It all depends what you want to keep in the tank.