Originally Posted by dragonx47
I've found the Whisper 10i to be too strong, and it is difficult to baffle using the water bottle trick, although I do know some that used filter sponge to baffle it. Sponges are generally better for bettas, but they require an air pump.
I did it in such a way that the water slightly "ripples" just on the surface, which is good since water standing still tends to get a film on top. This way the water gets the air at a low pace and the bettas don't seem to be bothered at all. They are actually swimming right through the half tank where the rippling takes place. I personally, in my case, find that using filter media and the baffling together works great.