To answer your questions about my staining,. the stain is dark colored,it makes my water look darker not crystal blue.it starts at the water line all around the pool then streaks down the sides. the place i purchased the pool came out and power washed the sides, that didn’t help. I have scrubbed the pool, it still comes back. The stain reminds me of "bathtub ring".
It sounds as though you may have an issue with a metal or other contaminant from your fresh water. This would be true if the stain only comes back after you have topped off the pool with fresh water. If after you have treated it, it is absent until the addition of fresh water, then you know that it is something in that. If so, I would add regular dosage of metal/stain remover and an extra dose any time you top off with fresh water.
Did you find this answer helpful? View more stains FAQs here.