Help with receding candy cane coral

[edikpok]

2 open large (and 2 closed) brains, acans, frogspawn, torch, zoa, gsp, a few softies.

Come to think of it, I did notice that 2 heads of another euphylia coral died over the past couple of weeks. All the other ones seem to be fine. The non affected candy canes open up nicely too...

YES - for the new batch of salt. Just opened the new bucket 3 weeks ago which could coincide with when the problems bugun. Same IO salt though - could this be the problem???