Hey guys, I just noticed there is some white fluff on one of my (brand new) fish's fins.... He's been quarantined, but I want to get a jump start on protecting the rest of my tank (especially because most my fish are new, bought within the past week). I have an old bottle of pimafix that is expired. Is there any harm in using this? I will buy a new bottle in about 5-6 hours when I have access to a car, I just really want to get a jump start on preventing a problem in my tank. I've also heard that you cannot have activated carbon in a filter when using pimafix. Is this true? I'm hoping to avoid swapping out my filter media, as my tank just finished a minicycle.... (like so recently that I'm still dosing stability to make sure it doesn't crash). If I do need to swap out the filter media, can I put the filter with carbon just in the tank (not in the filter) to maintain that bacteria colony so I can put it back in the filter when the medicating is done? Or any suggestions on medication that might work better than pimafix? I should also note that I have a few red cherry shrimp. So only suggestions that are safe for them please!