White stuff in my tank

[Gavmoore23]

Hi,

just a quick question, last night i came home to find that my tank had these white bits in the water. the best way to describe them is they look like bits of skin from inside your mouth??

What are they?? there wasn't loads of them but there was quite a few.

btw, the water is RO water.

Thanks

 

[Bomag]

hiya mate is it in the tank without fish in it

 

[Gavmoore23]

there is only 2 yellow labs which were put in the day before.