When I opened my pool (22,000 gallons) this season, it had a lot of leaves and run off from heavy rains over the winter. Even though I knew I had metals in my well water, I elected to use it when vacuuming to waste over several days of getting the junk out. I had used sequestrant in the past with good success, so I figured I would do the same this season.
However, once free of trash and the water balanced, my water was clear, but brown. I put some water in a white bucket and noted the color was yellow. Over a couple of weeks, I used about a gallon of sequestrant. The color never changed. The local pool stores where all scratching their head. No iron, no copper. Must be manganese. Use more sequestrant, I was told.
Well I finally decided to drain most of the pool (all except 8 or 9,000 gallons) and start over (with city water). Now the pool is much clearer, but the water still has a yellow tint. The liner is stained brown, but ascorbic acid seems to do the trick with some test spots I have tried. I figure at this point I have diluted what ever well water was in the pool to a point where a sequestrant will be effective. The sequestrant was added 12 hours ago, but it appears it is not going to do the job, again.
I am posting this to see what other ideas you guys may have as to why the water has a yellow tint, is clear, free of algae, minimum phosphates, but will not respond to a SEA KLEAR sequestrant or any other brand I have tried. I consider this a short term problem, because I will be replacing the liner in the next 6 weeks or so and using 100% city water. But the wife wants a pretty pool in the meantime.
Currently, the FC is 1, TC is 1, TA is 100, PH is 7.2, CYA is 10 to 20.