Gray stains, scaling pool floor, what is it and how to remedy

Hi, new to this forum and pool ownership so I am turning to this forum to get some guidance on a situation that is affecting my below ground pool. Recently I have noticed some gray spot on the bottom of the pool with a hard white/light gray elevated center which seems to be expanding, multiple spots throughout the pool. Some of about the size of a a half dollar and new buds are now forming throughout the pool. I was able to remove the precipitation with a steel brush leaving a smooth finish but the stain seems to be embedded into the pool's surface. I have treated the pool with Scaletec which has softened the precipitation but I have not notice any clearing of the gray stains and the gray buds seem to continue to appear.
I have a 14,000 pool with a saltwater chlorinator. Below are the results of my last water test:
Total Free Chlorine: 4ppm
PH: 8.0 (added acid to reduce the PH)
Total Alkalinity: 115ppm
Calcium Hardness: 315ppm
Stabilizer: 60ppm
Total Dissolved Solids: 3,900ppm
Salt: 2,800ppm

Any advice as to what could be the cause and how to remedy would be greatly appreciated. Would love to be able to get rid of the gray stains.

Hi,
I am not sure what is going, because there are only two numbers I wonder about, and only one that's a serious concern: pH.
For starters, I would get the pH down to the low 7 range, like 7.2. If you find pH keeps rising (common with SWCG pools), then you should lower your total alkalinity until pH is stable, even if that TA number is 60 or 70. High pH increases scaling and lowers chlorine's effectiveness.

I am less concerned about salt being 2800--that should not affect the scaling issue. It should be 3000. But that is minor.

I am assuming, of course, it is scale and not some weird biological growth, which requires a different treatment.

Thanks, will give it a shot.