Critter ID

[coralcoralcoral10]

Hello I was looking at my filter today and saw that they are covered in spirorbi worms and these. Can someone tell me wha these are? Thank you

 

[Llyod276]

Look like pineapple sponges. Leave em be. They do no harm.

 

[vetteguy53081]

They are pineapple sponge and oten found in shaded areas. They are short lived and are formed by silicates aften in a newer tank OR rodi unit which the Di resin is used up.

 

[coralcoralcoral10]

Thank you so much!