Which Hydor Koralia for flow?

Hi Gilles,

I used two koralia 2's (not sure what that translates to in the new evolution models) within my 37 gallon tank prior to upgrading the filter, for flow. They worked well. I found that the slots where the water is sucked in doesn't tend to be a problem with shrimp. My MP-10 slots were twice as wide and whacked some shrimp before I placed the foam screen on the outside. I also found that the "cover", which I don't think the evolution models have, reduced and narrowed the flow. I preferred to run mine without the end covers.

I think it depends on your goals for the pumps. If you are trying to help water move through some thicker planting areas, I think the nanos would do well. If you are looking to improve general broad flow I would choose the evolutions. Maybe one evolution and one nano. That might give the most flexibility.

How big is the tank?