Infection???

[Glass House Reef]

Can anyone help identify what this is on my acan colony and what to do about it? Otherwise colony looks very healthy..just want to keep it that way.

parameters:
Salinity: 1.024
pH: 8.2
Alk: 9.7
Calcium:420
Mag: 1310
Phos: 0.15
Nitrates: struggle to stay above zero

 

[vetteguy53081]

May be poriferan sponge. Take a dental pick or small crochet needle and gently pull it off the acan…….. GENTLY