pineapplesponge

Hi Everyone, are these pineapple sponges? And should i be concerned? I have a 38 gallon saltwater. Everything and everyone else is happy and healthy on the tank. Any help is appreciated!!

Hi all! So I get that they’re harmless except when there are more and more each day. Any way to rid or cut down the number of them. Also running a UV also.

I’ve begun to notice 2 new organisms slowly appear on my live rock in areas of low light. tank is a little over a year old. Attached are 2 pictures the organism that is in the pic with one circle, I thought at first was a small feather duster but the frill ends do t seem to retract when...