Silver flake particles in pool filter sand.

I'm changing over a tank's substrate to pool filter sand. Purchased the sand today and during the washing I noticed small black particles and small silver particles. The black specs don't bother me.. adds a little character. The small silver particles I'm not sure about. They are a shiny flake like mica.

I know tons of people use pool filter sand for substrate. Just wondered what the silver particles are.

 

Are they floating particles? I have some black grains in my PFS but no silver.

 

They stay suspended and runoff when you wash. But they don't float.

 

Hmm no idea. Maybe someone else who has PFS may know. Sorry.

 

Could they be Mica (phyllosilicate) ?

 

I think it is Mica. I kept some of the runoff from washing and then let the "settlement" dry. It looked like "glitter" in the mix and a close inspection did reveal that it looks like small tiny thin flakes of mica.

 

Didn't notice any in my pfs, but maybe it depends on the source.

 

I assume mica is safe for all stock.... I have Cory's that will be rootin' in it. (That's why were are using sand.) I tried to rinse out as much as possible but it's pretty difficult. You can only rinse sand so many times