Monti plate white stuff

[4tanks]

HI does anybody know what this white stuff is under my monti plate thanks in advance

 

[nereefpat]

Sponge

 

[4tanks]

Thanks I was hoping just sponge it looks healthy on top I have a lot of pinaeaple sponge in the tank at the moment not sure what the green growth is tho that can be seen in the last picture on the sponge

 

[vetteguy53081]

Ball sponge and I would try to get it off the monti

 

[4tanks]

Ball sponge and I would try to get it off the monti

OK thanks are they distructive