Is this mold or white fungus?

[findingDory]

Hi, recently my 7 inch sea hare passed and i removed its remains after 2 days since i didnt know it had died until i saw it decay. Then did a 50% water change. I am seeing these white moldy looki g stuff do you know what this could be?

 

[vetteguy53081]

Hi, recently my 7 inch sea hare passed and i removed its remains after 2 days since i didnt know it had died until i saw it decay. Then did a 50% water change. I am seeing these white moldy looki g stuff do you know what this could be?

Pic fuzzy but appears to be ciliate sponge
You can peel it off or if stubborn, scrub off with a firm toothbrush OUTSIDE of the tank in a container of tank water