Hi all, new to the hobby here. tank is about 2 months old (after cycling), I've had this mushroom for about a month. It's usually big and puffy but today it's small and angry and has this odd dark spot on it. It looks as if the flesh is receding there or something. Did a 25% water change today so I doubt it's my water parameters. Should I be cutting off that part or just wait and see? The spot doesn't move at all so I don't think it's a flatworm. I recently lost my two hammers to BJD so I'm not trying to take any chances here. Any help is greatly appreciated!
