What is this

[corsicoreef]

Hi all, any idea what is this attached to the bottom of the wave maker?
Thanks

 

[ISpeakForTheSeas]

Probably a pineapple sponge - a harmless filter feeder; they tend to boom then bust in population, eventually going away on their own.

 

[corsicoreef]

Thanks a lot.
Now googling for pineapple sponge it looks very alike to what I see in my tank.

 

[vetteguy53081]

Agree. Can be from new rock, new sand, from tap water if used and expired or leaking Di Resin cartridges.
These are short lived and will dissipate as silicates reduce. You can peel them off with the edge of a credit card into a net if they are too many
They are not harmful and cherish algae if they get any

 

[corsicoreef]

I spotted only one, might there be others, but it's not a concern.
I was just curious...
Thanks