What's this?

[jahel318]

Anyone know what this is growing on the rock?

 

[nathan1986]

Pineapple sponge. Common in newely set up tanks (IMO) nice little filter feeder

 

[nathan1986]

My gf's biocube was full of them for awhile. Now they are only in the back chamber of her biocube

 

[clearwatereefer]

i had a few in my display,but had a ton in my sump

 

[Reefpilot11]

I've got a good amount in my overflow

 

[jahel318]

ok cool I thought they were pests and I tossed a piece of small rock that was full of them....oooops!