What is this?

[Gavin1274]

Hello everyone, I am doing a big water change on my tank along with cleaning all my filters and when I started opening up the filters and cleaning them I started seeing all these little things growing on them?? What is this?? Thank you

 

[Ron Reefman]

They look like pineapple sponges, common bloom in the early months of a tank.

Account Suspended

 

[KJ]

^^^ Agree.