I'm dealing with a brown pool. FC has been holding for almost 2 weeks, I've treated for the trace amount of iron that's in the water (Metal Magic with pH at 7.8). The filter is in good shape. Here's what I'm wondering:
The pool was built last year and PB closed it. Unfortunately, they didn't bother to test the calcium, which was 90ppm when I arrived on the scene. The plaster is now very badly etched starting about a foot down the wall (where it was drained to over the winter).
The plaster itself is a dark gray/brown. Is it possible that pigment from the dissolved plaster is staining the water? It's a little out there, but I'm sure it's not algae and I'm pretty convinced at this point it's not metal related. My original conspiracy theory was that a large amount of red clay got in the pool, but it's had plenty of time to filter that out.
It may not even matter. IMO the PB owes the PO a new surface, but since I thought of the possibility I'd at least like to know whether or not it's plausible.