No drain acid wash

We will be doing a second follow up no drain acid wash on our 30,000 gallon pool. The first time around we used 5.5 gallons of acid with good results in removing residual plaster dust leftover from the original startup. Now there are a few stubborn patches of a milky gray color on the pool floor, and a few areas on the walls.

The plaster is Stonescapes Tahoe Blue and for the most part looks better than ever.

It was suggested to use from 10 - 12 gallons of acid to clean up the rest of the dust. Does this sound like the right amount? I was told we did not use enough the first time and that's why we still have a few areas that need to cleaned up.

I assume you are talking about the United Chemical product and process?

Unfortunately, I have ZERO experience with that product.