Anyone know what these things are??

[Strydon]

Just noticed 3 of these things growing in my tank earlier today. Two on one of my rocks and one on the skeleton of my frogspawn. Hopefully these pics aren't terrible and you guys can see enough. I checked the pest threads and didn't really see anything like this... Anyone have any idea what this is?

 

[blaxsun]

Pineapple sponge. Harmless and benefit to your reef.

 

[Reefing102]

Pineapple sponge. Harmless and benefit to your reef.

This^^^

 

[Strydon]

beautiful! Thanks for the quick reply!