Algae or Rust?

[denniston]

As hard as I try, shortly after I vacuum the pool this “stuff” settles into the grooves in the bottom of the pool. Last time I decided to vacuum it to waste and it seems to have helped.

I’m wondering if it’s actually rush and is too fine to be filters by the sand filter?

If it is rust, can I put some polyester filling in the skimmer basket and catch it?

 

[mknauss]

Can you post a full set of test results? Typically that implies dead algae. So you have live algae.