Right now I have my betta in a plastic bowl holding like 1/2 gallon or a little less. He was very happy to get out of walmart tiny bowl. I'm still figuring out what's wrong with my 10 gallon tank. I'm wandering how often to change the water and how much to change if not the whole thing. (Note: there's never any left over food to sit at bottom of bowl and there's no air pump or filter as of now). If I change the whole thing then when I get new bowl water do I need to acclimate him by floating in a bag with old water on top of new water? Thanks!