ray has deathcurl

[krnbk1]

New to the forum Hi everyone. I came home from work today and my ray was just chilling at the top of the tank. He's still breathing, I poked him an he did move. Also he has a few white spots on his top. If im correct he is a mono ray/teacup ray. When i left for work this morning he looked fine. And same as all the other nights. Please help.

Thanks

also water,sand and filter is all good.

 

[NewETown]

I have no personal experience with rays but my first questions would be:
What is the temperature and did you lose power at any point during the day?
Did you do a water change recently?
What size tank and what is your typical water change regime?
How long have you had him?