ID please

[ReefMichael]

I was working in the sump today and found these all through the sump area. Mostly on the glass surfaces. What would they be? Good or bad? Thank you in advance.

 

[Zach B]

Looks like a sponge to me

 

[ReefMichael]

I was working in the sump today and found these all through the sump area. Mostly on the glass surfaces. What would they be? Good or bad? Thank you in advance.

 

[Zach B]

Sponges. Beneficial filter feeder

 

[ReefMichael]

Sponges. Beneficial filter feeder

Thanks. Is there a point that they would get out of hand and become more harmful than good to where I should clean some out?

 

[Zach B]

I have a ton in my sump, I wouldn't bother with them. They are usually a good thing. There are other sponges that can spread in a tank fast but I believe the ones you have are not harmful. Especially in a sump. Best of luck :)