Recomended Internal Filter For 20 Gallon Tank

[hviviers75]

Hello all

I have got a 20 gallon fish tank with a aquaclear 50 hob filter. I need to know what the recomended internal filter/powerhead filter I must use. At the moment I have got a 700liter Resun internal filter but it gives to much watee movement I need something that will be sufficient for my tank. It must just supply enough extra movement/current. Your help will be much appreciated.

Thanks.