New reefer question... what am I looking at here?

[PoeLagoon]

What am I looking at here? I have a few of these on the bottom of some rocks.

 

[vetteguy53081]

Pineapple sponges
generally is shady areas of tanks and are formed from silicates found in newer systems and from RODI resins. they are short lived and harmless

 

[PoeLagoon]

Pineapple sponges
generally is shady areas of tanks and are formed from silicates found in newer systems and from RODI resins. they are short lived and harmless

Thanks for the quick reply. One is on the stock of a hammer frag. Should I remove or just let it ride.