deepwater zoa help

[Aquaria]

well i noticed today a few black snails that look almost like pyrimidii or w/e but black they were on the zoa. also i noticed hair algae (mabey thats what the black snails are eating)starting to grow on the frag area and am moving to a more highflow area. this clam thing growing out of the frag is bugging me to its bgetting bigger might break it all up glue what i can back to the frag see if it pulls though any reason not to?