Small White Balls Of Fluff

[tez2k007]

This morning I have noticed a couple of tiny white fluffy balls on my gravel. What are they and how do i get rid of them? Also how are they appearing.

 

[tez2k007]

anyone??

 

[SharonCC]

Could any leftover food have gone "moldy"...

 

[tez2k007]

Could any leftover food have gone "moldy"...

Possibly Im not sure. It only seems to be on the gravel so im gonna do a gravel clean and water change when I get in from work.