Identify

[mrme123]

Any idea what this white thing is? Is just popped up in my tank the towel day and it’s attached to the overflow box

 

[Reefing_with_John]

Can you post more clear picture?

 

[mrme123]

Beat I can do. It’s at the back of the tank

 

[firerescue]

Maybe some sort of sponge?

 

[mrme123]

Maybe some sort of sponge?

Possible. It’s moved to different parts of the tank. I never see it move, just one day it’s somewhere else