Dumb polyp question

TL1000RSquid

AC Members
Apr 6, 2011
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I have a couple rocks completely overgrown with starburst polyps and xenia that I'm going to make some frags out of to get rid of. Is there anything that can coexist on the same rock as either that wont end up getting overrun?
 
i have had a kenya tree growing out of a rock completely covered in GSP and it is healthy. kinda looks like a tree in a field of grass.
 
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