Muriatic Acid Treatment For Hydrazzo Marks?


LifeTime Supporter
Jun 12, 2008
Thornton, PA
Hey Folks-

Had my pool installed recently and they finished it this spring. The Plaster/ Hydrazzo crew came out on a rainy Thursday to install the Hydrazzo, and took the better part of the day to finish the job. When the rain started, the built a tent over my pool so the could get the work done -that may be irrelivant -not sure.

The following day, crew #2 showed up to polish the Hydrazzo. These guys spent somewhere in the order of 10 hours doing the polishing and when they were done, there were several marks on my Hydrazzo that I asked about. These were; scuff marks from someone's boots on the floor, light streaks down the walls, and it looks to me that they polished the heck out of the walls and stopped at the floor because there is a distinct line where the walls transition to the floor. Now I know these finishes never look perfect, and that there are natural blemishes, but these marks all seem installer related to me. I asked crew #2 and their crew chief said "Just keep brushing, it will go away..."

Well, I brushed the heck out of that pool for three+ weeks and saw no improvement so I called Carlton and they sent a guy out to look at it. He agreed that the marks need to be addressed and indicated that one of the crews (not sure which one, did not keep the Hydrazzo wet enough. He offered me 2 options;
1) send a guy down with SCUBA gear to re-polish -which would "make the water cloudy and would not get it all". [Possibly spike my CH as well.]
2) "Treat it chemically" with the water still in it. -Which, now get this, would involve 20+ gallons of Muriatic Acid in my well balanced pool water left in there over several days with lots of brushing.

He seemed to think option #2 would make the finish look consistent and not have any ill effects of the surface or product longevity. I REALLY LOVE the smoothness of my current finish. He re-assured me that would not change. I asked him if he would at least wait until the end of the season to crush my PH and he agreed. Now I am having second thoughts. It just seems as though it can't not have any ill effects, but perhaps by the time anything bad shows up, my warranty will be expired and I'll have no recourse.

I'd appreciate any insights any of you may have as to whether this is the right approach and any suggestions you may have.

Is this a common practice?


The second procedure is an 'acid startup' procedure and is a common way to start new plaster (yes, you have a plaster pool--exposed aggregate finishes are also plaster). It is actually a very common method with exposed aggregates.