This is known as valonia better called bubble algae.
Take a small needle and have 3/8 tubing ready and attach to end of tubing with rubber band and pop each one and siphon at same time- You will have removed all spores and foreign material in area.
Had to do this in the past with birdsnest coral and was gone 100%.
Other option is to add pitho crabs or emerald crabs (which I do not trust) which will eat them