[Quinn]

Ethically? Well you're not a research institution so at least you don't have to go through the ethics committee. I was also thinking about this and the main difficulty in my mind is ensuring both your control and test groups are infected with ich, and to the same severity. If you really want to discuss ethics I suppose one could take issue with your subjects - since it seems most often ich affects tangs, you'd want to include them in your study, along with other types of fish. The problem is, tangs and numerous other species don't breed in captivity. But I know if I were on the ethics committee and a qualified researcher wanted to do this research, I would approve.