Coral randomly started overgrowing in an established tank

[kamstutz]

Hi, everyone! I have been taking care of a reef tank for a school club for the past six months. The tank itself has been up and running for several years. A couple months ago, I noticed this (presumed) coral starting to grow on the rocks in between two sections of what I think are button polyps. Over time, it has continued spreading until it reached the lower section of polyps. Now it looks like they are overgrowing and killing those polyps. I need help identifying what it is and how to get rid of it. Thank you! (This was the best picture I could get. Unfortunately, where it is in the tank, there is a horrible refraction that makes it difficult to get good detail.)

 

[blaxsun]

Are we referring to the palythoas?

 

[mdb_talon]

It is hard to tell in pic but from what I can see I would say pavona coral.

As for killing the polyps I would throw a party for it for doing so.

 

[EeyoreIsMySpiritAnimal]

+1 for Pavona. Not a lot you can do to get rid of it besides fragging off the part(s) of the rock containing it. FWIW, it's a pretty coral so you might try isolating some on an "island" and letting it take over the rest of the polyps.

 

[olonmv]

I’d prefer the pavona over the paly’s any day especially in an environment with kiddos.

 

[kamstutz]

Thank you everyone for your insightful responses! I will let the other club officers know so we can decide what we want to do with it.