Hydrazzo bleaching

[Rogilio]

Hello,
I have a Hydrazzo finished pool that is approximately 8 years old - original color was medium/dark blue. Approximately 7 years ago it started getting bleach spots (pics attached) - at the time, we used tri-tabs and powder shock (changed to SWG and TFP methodology about 6 years ago). It seems like the hot tub is significantly worse than the pool (not sure if heat has anything to do with the bleaching).

Questions:

1. I am wondering if anyone has experienced anything similar to this and, if so, what the cause may be?
2. I am considering having the finish repolished and staining the entire pool and hot tub with a darker concrete muriatic acid stain in order to get a consistent color. Has anyone on the forum tried concrete muriatic acid stain on pool plaster? I tested it in an inconspicuous area 6 months ago and it seems to work.

Thank you in advance for any help you may offer.

 

[ajw22]

@onBalance wrote...

White Spotting of New Plaster Pools

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service...

www.troublefreepool.com

I have never heard of concrete muriatic acid stain being used on plaster. I would think it will etch and thin out the plaster.

 

[onBalance]

Performing an acid treatment of any kind may expose the original color of the plaster, but it will also leave the plaster surface etched and rough. It will also not last very long, meaning that the color will begin to fade again within a year.
IMO, the best remedy is to drain the pool and do a power-sand of the pool. That will expose the original color and leave the surface smooth. That procedure will also help the plaster and the color last longer.

 

[Rogilio]

Thank you onBalance. and ajw22 I was thinking of doing as you suggested onBalance and power sanding the pool. I am just not sure that it will get down to the original color, which is why i was considering the combination of power sanding, then acid staining a dark color. I really like the original deep blue, so i may just bite the bullet and resurface it.

 

[onBalance]

I am not familiar with concrete staining products for pool plaster. Concrete such as garage floors are not subject to being submerged in water 24/7. Perhaps the concrete stain treatment is not for restoring colored plaster pools because it wouldn't last very long. I hope you try to sand a small area and see what the results are. And hope you find a good remedy.