i like ParaGuard by SeaChem (makers of Prime). The name is a bit decieving but I looked into it more and its for parasites, bacteria, fungus and viral infections. i'm using it right now for fungus and seems to be working. i also have Jungle Fungus Eliminator but i don't like it as much because you have to remove active carbon from the filter and thats not very convenient for me as i have to cut the filter cartridge open to get to the carbon. i've never really had results with it but I think its because I didn't use it long enough. I like anything thats a liquid and not a powder/granular substance like the fungus eliminator. i've used melafix too and had good results with it as well. so, to make a long post short, i like ParaGuard and Melafix haha!