ethnics - Added the Gar to my tank last night, and before I did I did a 75% water change. It is a 20gal tall used as a quarrantine/hospital/fry tank. There is also a bircher that I got at the same time, who is divided from him. The bircher is showing slight sins of fin rot so I added Mela and Pima flex as a preventative measure. From the 3-4 years of experience wtih aquariums I have learned fresh water is great for growth and aiding the resistance of illness. I could just clean thouroughly clean the filter, but I would not touch the bio-wheel, since it has been a while since I did that.