I have just resurfaced my IG pool with Pebble Tec Tahoe Blue finish and the PB did a pretty poor job on the initial acid washing to expose the pebble aggregate. There are large patches of excess cream in many places as well as in the corners of the steps and benches where the pebbles are not fully exposed due to the excess cement left on them. The Pebble Tec rep had the PB to start a no drain acid bath process to supposedly loosen up the excess cream and even out the "blotchy" appearance of the pebble finish. TWELVE gallons of 31% muratic acid was added to my 18k gallon pool and a small utility pump was dropped into the deep end with a 1 inch discharge hose that is circulating the water back up to the shallow end of the pool. The pool pump equipment was shut off for the next few days so the acidic water does not circulate through the pump, filter, heat pump and other equipment during the acid bath process.
It's been about 12 hours since they started the procedure and I'm noticing that all of the "blotchy" areas with the excess cream are looking a lot darker, and much more noticeable, than they were before. I know it takes about 3-4 days for the acid bath to supposedly work on dissolving the cream so it can be brushed away but it's too soon yet for the brushing to help much with exposing the underlying aggregate. But is it normal for the excess cream to darken in appearance and become much more prominent during this procedure?
I'm also planning to add borates to the pool and was planning to use the 66 pounds of 20 Mule Team borax (needed to get a 50ppm borate level in 18k gallons) as the initial neutralizing agent to help raise the pH back up to normal range in a few days. Of course, additional baking soda or soda ash may also be needed to help neutralize the 12 gallons of acid that was used for the acid bath. Is this a good way of getting the borates level from 0 to 50?
Water chemistry prior to starting the no drain acid wash procedure:
FC: 4.5, CC: 0, TC: 4.5
Any advice is appreciated....Thanks!