a update:
I tried to remove the algae by tweezers, but it was too fine to nip it. the cotton swab(cosmetic stuff from wife's drawer) was used to clean the algae in between the zoa polys. It worked okay, not super cleaned but removed 75% of them. Following that, the colony was dipped in a 1:2 H2O2 and tank water solution for 3 minutes.
The colony is not opening up at this time, it has been in tank for 5 days.