SOS! This morning my light turned on and I did my usual check of all my fish while they ate. I noticed this red bump near my female platys anal fin. I immediately checked water parameters and they were all in typical range. There have been no new fish or anything added to the tank. I do 20-30% water changes every Sunday. This particular platy was a ‘rescue’ from being flushed because she was ‘ugly.’ I’ve had her for about two years or more in this same tank.
The internet said tumor or parasite and to euthanize so I decided to come here instead!
Temp - 76.9, Nitrite 0, Nitrate <30, Ammonia 0, PH 8.4
45 gallon tank with her, 10 black mollys, 7 corycats, and one rubberlip pleco with a sponge filter and a Fluval 70
I’m not sure what to do! Any advice would be more than appreciated!