Thanks for the reply. I am not able to scrape a piece of the scale off to test with vinegar. The scale does not hold together into anything that I can capture. All of the scale is on the bottom or on the pool side within a few inches of the bottom and it just disintegrates when I scrap at it. I tried to put some vinegar in a glass and then move the glass down the side of the pool to the scale and hold it there. Didn't see any fizzing but it was hard to hold for any length of time and hard to see anything with clarity.

I have lowered the pH and am holding at 7.