Sponge ID or something?

[wmv]

Hi everyone, I decided to do a filter cleaning on my AIO today and found a ton of whatever these things are growing back there. You can’t see in the photo but they kind of have feathery looking tips. I’m assuming these are common I just can’t remember what they are and if they’re good or bad. Thanks

 

[Dipi]

Pineapple sponge mayne?

 

[twentyleagues]

Pineapple sponge.

 

[wmv]

Yup that's right, thanks guys