At least I think it’s a favia. I’m horrible with names. Anyway, I was thinking the favia would just sting the paly and keep it away but not sure. Thoughts?
Palys, depending on the species, can be pretty invasive and grow like weeds. I have texas trash palys that hitchhiked in on my live rock and have take over some of the aquascape to the detriment of nicer corals. In addition, favias tend to grow rather slowly so even if these palys are slower growing, they will likely spread faster than the favia will.
I would try to isolate the palys or move the favia as the palys will likely grow up the rock and take up the real estate for the favia preventing them from growing.
I didn’t actually want fast growing paly on that side of the tank so maybe I’ll move them and try to kill what’s grown on the rock. Hard to get to though.
You can try scraping them off the rock with a scalpel/razor or tweezers, use the stainless steel straw method, or you could try using something like F-Aiptasia on them.