Can someone tell me what this is plz !!!!!

[Axselcintron]

 

[Mrc8858]

Welcome to AA glad you found us here those are pineapple sponges. Harmless filter feeder, you'll often see a large bloom of them during the first few months of setup or if there are excessive nutrients in the water.

 

[Axselcintron]

Thanks I had the tank for a year now