I had that happen to one of my pups/young rays
Best and quickest treatment without treating the tank.
Scoop up the ray gently into a bowl with a little tank water, pour some methylene blue on the affected area of the tail and gently immediately put her back in the tank.
Dont put the water in the bowl back in the tank
It will start healing immediately
Overnight the fungusy fluff will fall off and the tail will heal
I have never seem anything heal as fast as this does
If you have someone you can trust to help you, net her just to water level and put a few drops on the tail.
Best and quickest treatment without treating the tank.
Scoop up the ray gently into a bowl with a little tank water, pour some methylene blue on the affected area of the tail and gently immediately put her back in the tank.
Dont put the water in the bowl back in the tank
It will start healing immediately
Overnight the fungusy fluff will fall off and the tail will heal
I have never seem anything heal as fast as this does
If you have someone you can trust to help you, net her just to water level and put a few drops on the tail.