I'm new here, and would appreciate your expert advice!
I have a 9 year old plaster pool, and with our basic knowledge, we have never had an issue. We try to keep the water balanced and have not had any problems. Until now.
I backwashed last week, and the autofill kicked in. That night I shocked the pool. The next day I woke up to what looked like dirt in the pool. Since we are in Az and in the desert, it's not unusual for a dust storm to move in and leave a mess behind! So, my first thought was that it was dirt - it was a light tan, streaky in places, mottled looking in places. But when the cleaner didn't pick it up, and the brush didn't move it, I knew it was something else. My local pool guys (that seriously have never steered me wrong), told me to shock again, with massive doses of shock, so now my chlorine is completely off the chart. Anyway, when that did nothing, I took them some more pics - and this time he told me to use "Pool Stain Treat" by United Chemical. He said it was scale. As my PH was on the high of normal, he told me to lower ph first, but I did not need to be concerned by the chlorine, and could use the stain treat without lowering the chlorine. Of course, as soon as I added the acid to the pool, I read the directions for the "Pool Stain Treat" and saw that the Stain Treat would also lower acid - which of course it did. So, it was in the pool overnight, and I don't see any difference in the staining,(hubby says it's lighter, I'm not sure),but PH is really low, chlorine really high. Here are some questions:
1. How long do I need to wait to know if this is going to work? (husband says it's lighter, but I'm not sure)
2. My PH is now too low (in the 6's), do I need to bring this up immediately, or will low PH help remove the scale?
3. Any other advice you can give me?