nish11an

Thanks for the suggestion, I really appreciate it!

Water parameters are pretty stable. Temp 77-79, pH 7.2, GH 250 mg/L, KH 80 mg/L (basically moderately hard water). 0 ammonia and nitrites and nitrates stay around 10 ppm (my tank is heavily planted). I have not noticed similar injuries in any other of my fish though.

Hi, I’m pretty new to this hobby (1 month) and this is a platy I believe, which was one of my first fish. I noticed this morning this wound near its tail (picture attached). Did it get into a fight with any other fishes (I have a 40 gallon breeder tank with mostly other livebearers and a couple of pearl gouramis)? Is this an infection? Any help will be appreciated!