I bought 5 Albino Corys today. It seems as though all of their fins have been chewed on a bit. When I tested the store water in the bag the nitrates were ridiculously high like 200 ppm high (I've never seen the test so pink). I don't remember what other fish were in the tank at the store. Is this a case of fin nipping or fin rot? And how long will it take for them to grow back their fins? Additionally, I have 6 black neons in the tank as well. If it is fin rot, are they in danger of contracting it as well?