I need a good filter for a 5.5g tank. It is heavily planted, and it houses two bettas with a plastic mesh divider. The tank is right by my bed, so I need a very quiet filter.
I would like to change my substrate to sand, because I've read many positive things about it.
For the filter, I am considering two options: AquaClear 20, or sponge filter with a power head. I don't want to get an air pump, because its too noisy for me.
As I said, the tank is planted, so I am mainly looking for good mechanical filtration to remove plant debris and fish waste. My main concern with AquaClear is that it will stir up the sand too much (maybe I should stick with gravel?). The idea is to move a divider to about 1/3 of the tank, and put my smallest betta in there. He is very slow moving due to his large fins, and he mainly hides out in the plants. The larger active betta would go into the large partition with the AquaClear. The intake would be covered with a sponge, and I will construct something to soften the outflow.
The second option is one or two sponge filters. I have never used sponge filters before, and I don't now how efficient they are at mechanical filtration.
What would you recommend?