I need to treat a fish quickly with antibiotic. People seem to have a lot of luck with furan-2. It says it will not harm your bio filter, but I don't see how this is possible. The only thing in the tank is my lion (which I am treating) and a CC star. I would love to just treat in place, but I don't want to destroy my live rock and sandbed. Does this product really do what they say? Any experiences....