Sponge filter ?'s can't find answer...

[Sb5366]

I have a 20 L I just set up. I have a quite large double sponge filter and a pump rated up to 60 gal. The bubbles break the water surface, but how do I tell if a current is created?
Thank you!!!

 

[Canecorsonewt]

I have a 10 gallon with a double sponge filter. I do not have any under water current. I know this because none of my plants move under water. You can sink some fish flakes under water see if it moves around. But you shouldn't have much current under water with sponge filter. I think you don't want under water current the top might be fine. But I have telescope air out let i face it to the corner of my aquarium and my floating dock. It just ripples the top of the water

 

[auntiejude]

If you don't have any current how is the water going to circulate to be filtered? All filter create current, that's how they work. The trick is to keep the flow gentle, most sponge filters are fine.