they are digitate hydroids.
they usually can wear its course but not always as in my case.
dip all you like the dips do nothing , peps will eat them but not faster then they can reproduce. ive tried every dip on the market and in every concentration and lenght.....no such luck.
i am currently tearing down my tank because of this type of hydroids, while their sting is mild compared to other hydroids they do seem to bother zoos more than anything else and spread really fast in the end covering your rock completely and hiding in between the polyps
reefcentral has a thread about this type of hydroid , ive been battling this for about 7 mths now to the point where there are thousands......there is no getting rid of them without treating the tank as a whole.
manual removal with tweasers will help in your case as the numbers are small, h2o2 does kill them as well but the concentration and time needed also kills the corals.
good luck
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