I have a Betta tank and it stays dirty??? I have one fake plant in there and a couple of rocks. I gravel vac and clean every monday adding new water and a little salt and some Stress stuff. I have it at work so on the weekends I put the little 3-day feeders in there. The problem is, is that it wont come clean. The snail in there has green algae all over it. I dont understand??? What would make it so dirty??? The pics are attached. There is a clean tank, dirty tank, clean sncail, sidrty snail. What can I do to fix this problem???

