Changing to Mag 12's?

[Brucewrs]

Any use 2 Mag 12's for a return?I have a 210 mostly fish with dual drilled overflows. One pump for each return.I have no room for an external pump.I figured if one pump goes I have a back up.
Just curious if anyone is running the same combo?I had 2 Resun King 5's (1500gph each)but I think they were a no frills brand that came with the tank when I bought it.Plus no one sells the impellers for them.I wanted something a little better.I plan on using pvc with a union and a ball valve to adjust the flow. Thanks

[sjm817]

I wouldn't use that much return flow. If you plan on plumbing them into your overflows, you wont get it anyway. You need 1.5" plumbing to get the flow out of the Mag12s. 3/4" will cut the flow way back. A pair if Eheim 1260s would work nicely and flow great with 3/4". You should target 3 - 5x display size for return pump flow. This is ~ 650- 1000 GPH for your tank size. A pair of 1260s would be ~ 800 - 900 GPH. If you really want lots of return flow, a pair of 1262s would be more like 1400 - 1600 GPH but IMO is too much.