Stings on sps

[SnowManSnow]

Hi guys
A few sps frags have white strings on them. I can't shake the it off or blow it off. I'm not sure if it is COMING FROM the coral or something attached to the frag.

Can anyone help Id what is going on here?
Thank you

 

[fishy boy]

It might be sick

 

[SnowManSnow]

I was thinking reaction to red bug bites, but I can't find any