I have an 18x32 In ground pool, approx 25,000 gallons with sand filter and vinyl liner. The water is cloudy and there is a brown sand-like residue on the liner and it keeps returning after cleaning. We use an Aquabot for vacuuming. The last test readings showed everything normal but low CYA.
I also just added an HTH product called a clarifier. This seemed to make things worse.
Do I have mustard algae and if so what are my next steps? Is the aquabot making things worse?
I just bought 2 CYA producst that are coming in the mail in the next day or 2.

Need your help.