I think one of my new angels has ich, probably early stages, just a few white things on his/her long fins. I've completed a 3-day treatment for ich, but s/he's still hanging around in a quiet corner, not eating, only coming out occasionally (which is better than day 1). Last time I treated for ich, the fish were feeling better by the next day. Which is normal? Should this fish be feeling better by now? Is this just a dud fish and I should take it back? (Seems like a lot of trouble for a rather inexpensive fish, sorry if that sounds callous.)