Growth on rocks

[90rr]

hello i have a newer first sw tank that’s been running for about 9months the past few days I’ve noticed a growth on the rocks like stems all over any advise
Thank you

 

[PDR]

Welcome to R2R! It looks like vermetid snails to me. They are considered a pest, they may bother your coral or they may be harmless. It depends on the species. Manual removal is the most effective way to get rid of them.