Get a brush on them...outside of display tank if possible
Those are the burgundy ones...they’re terrible too
Don’t know what eats them
They bad, treat accordingly
If not...
That system is and will forever be infected with aiptasia
Once in the system...always in the system.
That system is small
The wise move is to frag all corals, and do NOT put anything from the tainted system into the new clean system without sterilization.
But that’s just me...