Just over a week ago I upped my Cardinal school by 4. I hadn't had much luck getting tetras from petland ( they died within 3 days) so I went to petsmart and got my fish there for the first time.The next day I noticed I couple of white spots, I read a lot about ick and because I have RCS and snails in my tank I can't medicate it. I turned up the temp of my tank slowly to 86 on Sunday and everyone seems to be ok. I noticed no spots Monday night so I did a 20% water change and vacuumed my sand. Tuesday night 3 of my cardinals have spots and today they all seem to be flashing and I have noticed my original cardinals have ripped fins.Since I upped the school all my tetras seem to be very skiddish and darting around the tank, which they didn't do before. So they are stressed.My water parameters are good, I had it tested before I introduced the new fish and I have the test strips. I do weekly water changes.I know it gets worse before it gets better but how long do I wait before I remove all my shrimp and snails and medicate the tank. Poor little fishes.