cotton growth???

[Mrjoshua313]

Hi I was wondering what this cottony growth looking thing was on my live rock.
Thanks about 4 weeks old. Cycled and just added small clean up crew Monday.

 

[Schism]

Hi I was wondering what this cottony growth looking thing was on my live rock.
Thanks about 4 weeks old. Cycled and just added small clean up crew Monday.

Hard to tell but likely a sponge the way it looks.