What is causing my zoas to die

[Rthines]

I recently got 2 zoa frags, one is thriving and the other looks like this. 2 of the 3 polyps are alive and occasionally come out during the day but the 3rd is definitely gone. One of the *not dead* ones is only attached via algae.

I didn't see any spiders or nudis after looking for a while. I'm not sure if these are able to be saved or if there's something that would threaten my good frag and need to be removed.

 

[goosemans]

Dip it in hydrogen peroxide mixed with tank water in a cup for a min or two to get the algae off it