I have a betta in with some corey cats. Very happy indeed as he is in a 20 gallon palace. Have a 45 gallon filter with a baffle made by a plastic bottle used to keep the water relatively still. Was told that airstones not needed although they look great. Was told they also will create too much turbulence in the water for a beta. What do you all say? Obviously he gets air from the filter opening and coming in as well as the inch or so of open space before the lid. Plenty of live plants too. What's your thought?