It doesn't look like growth on top but doesn't appear the flesh has completely peeled away either. Just that it's got that bleached appearance.Are the white spots growths on top of the cap, or spots shere the red flesh has peeled away leaving just the skeleton?
There could've been something dropped on it. Shouldn't be a flow issue, I cleaned the powerhead that's right by it a few weeks ago.Any fish dropping sand or pooping on that area? Could be a change in flow if the powerheads haven't been cleaned lately. If stuff settles on a spot, that area can die.