Brown Orange dirt wont go away

[rommulus]

Hello,
I have a brown orange dirt that has coated my pool surfaces, I can sweep it and it moves and acts like dirt but when my vacuum (Hayward Navigator Pro) goes over it, it doesn't appear to pick it up. In other words if I sweep right behind the vacuum I can see it move the dirt debris. The vacuum is pulling hard at least when I pull it towards the surface and put my hand over suction port. I am running about 2ppm Cl and 7.5-7.8 pH at the moment. I also cleaned the filter about a month ago. Just bought the house so not sure when any maintenance has been done. the vacuum is less than 3 months old though.
My guesses are:
1. Dirt and vacuum is a failure?
2. Algae but no idea why vacuum wont grab it.
3. I messed up the filter cleaning and it is DE in the pool.
Been chasing this for 3 days now and any ideas would be greatly appreciated.

Thanks

[Watermom]

Hi and welcome! By any chance do you fill your pool from a well? Post a complete set of water testing results taken from a drops-based test. Also tell us what type of pool you have, the volume and what type of filter you have.

[Poconos]

I've seen a similar situation on another pool where the fine dirt settles along the liner seams and when you go over with the vacuum it doesn't pick it up immediately. Going back and forth over the spot a few times and it will pick up. Don't really understand why but I suspect the design of the vacuum brush. My brush, which picks stuff up usually on the first pass, and this other one have different bristle patterns. Best I can suggest.
Al