Emergency help for rays

Hey guys, my rays have developed this over night and i have no idea what it could be! First sign was just slight redness and soreness on the skin, very small patch, what i thought was the ray rubbing on the heater guard or burning itself. The only difference recently was that I fed them frozen bloodworms, which were ORCA branded. Could this have caused this?

The rays have developed a white tissue paper like patch on their skin and it looks to be very sore and peeling. There doesn't seem to be any blood, just all white and papery looking. These are the best pics I could get on my cellphone. Last night they had no white patches at all, and I just looked at them and saw it like this.





Water params are as such :
Ammonia - 0ppm
Nitrite - 0ppm
Nitrate - 40-80ppm
pH - 6.8-7.0
Temp - 28 degrees celcius

Their behaviour is a bit strange, they lean on the wall a lot but undersides look clean white. no redness or burning at all.

Do weekly water changes and add prime to water to dechlorinate.
Can anybody work out what it is or what i can do to fix it? will the rays be okay? is this something that will kill them really quick??


Have to go to work, but i'll keep checking back on my mobile. Please help my rays!

Ahh! Who wouldve thought the flagtails would be suck pricks. To take off so much skin overnight!? So once there gone, just adding salt should be sweet to help them heal?