Hi everyone. I was just wondering what filter you people use for your turtle tanks. Right now I have 2 small painted tutles in a 20 gal with a Zoo-Med 318 filter that says it is made for up to 30 gals. But the water still turns green and nasty smelling afetr about a week. So I need a better filtern submersible or not, it doesnt matter, but I need it to be under $50 for the filter and any accecories(sp?) that it needs like extra filters or tubing and where I could find it. I would prefer to not order it online because I dont want to have to pay extra for shipping. Thanks for all your help.