Eheim Cannister!!!!

[TandG]

I have an Eheim 2217 cannister filter and I also have an Eheim 2217 dummy cannister filter (no pump). I would like to hook these up in series, but which one comes first?? I don't know if the pump is strong enough to pump through the dummy back to the tank or not. Any imput would be greatly appreciated!!! Thanks!

 

[Avalon]

Dummy cannister last. Use an adjustable powerhead to 'pull' the water out of it, or some variation of a push-pull design.

 

[TandG]

anybody have any reccomendations on good powreheads??