Calcium Scale on Natural Stone Tiles at Waterline

[lka674]

Is it safe to use a diluted mixture of say 2:1 or 1:1 solution of muriatic acid and pool water to spray onto those natural stone tiles and then use a scrubby pad or wire brush to remove it? (Safe meaning that it won't harm my stone) I've got the pool chemistry stabilized now so that we will avoid the scale in the future, but this is above the water line due to a TON of rain/thunderstorms which prevented me from getting out there to make sure the pH stayed where I usually want to keep it.....now the scale has formed all the way up to the coping above the water line. Gotta get that stuff off very soon while my pool temperature is still at least 76 degrees (burrr), any colder and I definitely won't be getting in there!

I am now keeping the CSI slightly negative to prevent it coming back.....we unfortunately have a high CH level - 460.

Many thanks!

 

[duraleigh]

Should be no problem. Test a small area but using muriatic is the common way to remove calcium from stone.

 

[lka674]

My husband went to town on trying to clean our natural stone pool tiles with diluted acid as discussed above and it's left almost all of the tiles around the pool dull. It looks worse now than before. I think that he may not have rinsed the tiles off well enough.

Any suggestions on anything I can do to restore the tiles? If you get them wet, they look great...but when they dry above the water line they almost look like they are covered in a thin layer of calcium scale all over again....but worse! As well, it seemed to do nothing to the algae in the grout lines. I want to come back with diluted bleach, but I worry about using anything further for fear of damaging the tiles even more.

Here are some pics of what I'm talking about.

Any help/suggestions are greatly appreciated!

Regards,
Laura