Well i use no chemicals in my tank. it is filled with well water and i do 2- 50% water changes weekly. I mean the only filtration i have other than my large scale water changes is a magnum350 canister filter with the carbon changed once a week. my nitrates are around 25 and nitrites and ammonia are zero. They were actually very similar in taste to tilapia and i use some butter and Stubb's spice rub , watch out. if you like fish youll like RD's. i ate the fish because i wanted too, the plus side was that i had a bunch of fellow MFK'ers to share pics of it with. it just made the whole experience that much better. it was truly one of the funnest meals i had aten because i knew i was gonna share with everyone. and hey if any of you live near san diego and have any large fish that need homes.......LET ME KNOW HAHAHA