I think that my fish have ich! I've noticed white spots on some of them, but then some of the spots seemed to go away. My question is, how do I treat it? I know that you need to raise the temperature, but how high? Do I buy a medication from the petstore? I don't want to mess up my cycle if I treat it. Currently the 20 gallon tank has 4 zebra danios and 4 black neon tetras.