Zoa growth question

[dbleoh7]

I have a colony of Sunny Ds that have now completely surrounded a rock with no space in between them. If I leave them will the ball keep growing bigger (ie their stalks keep getting longer and more zoas fill in the spaces) or do I need to frag some off onto another rock to make room for more to grow? Their stalks are already pretty long. Pic for reference

 

[fishface NJ]

My Sunny Ds grow like crazy. They will keep going. You might want to frag it. Be careful and wear eyes/nose mask and gloves.

 

[littlebigreef]

You're unlikely to have more grow out of the center unless there's areas that aren't colonized. What'll happen next is that they're grow down and across your substrate. No need to frag them if you don't want to.