White Scale Build Up in Tile Grout Lines

[mmcwhorter]

We re-tiled the pool last year...from below the water line up to the coping. I am noticing now two places near the elevated spa waterfall opening (splilway overflow in to the the main pool) that have a 2-3 inch long white crusty buildup in the vertical grout lines of the tile. Since the grout is also white, it is not to noticeable unless you are close. I have seen these in the past near spillways on other pools...and am assuming it is related to the splashing and/or churning or the water. You can definitely feel the elevated rough bumps with your fingers.

So, I am aware that MA will remove this, but am looking to see if there is something more gentle...or maybe I can start with a 10% solution MA/H20 and work my way up to stronger if it does not come off.

I'm sure this is a pretty common problem. Didn't find it in other posts

Thoughts?

 

[rphpool]

I have a travertine spa spillover and that happens to me also. I use acid water mix and stiff brush to get it off.

 

[pooldv]

Yes, it is fairly common. It is called efflorescence. It occurs when there is water behind the grout/tile/stone and it pushes the minerals through. Acid and a stiff bristled brush. Diluting the acid is fine. The acid, even undiluted won't have any impact to the tile and minimal impact to the grout or stone. You may be able to use a chisel, screwdriver or scraper to knock the efflorescence off manually. If you can eliminate the water behind it then it will stop. If not, it usually stops eventually after the pathway closes up, the water finds another path or there aren't any minerals left to push through.

 

[mmcwhorter]

Very interesting. I thought it was coming from the splashing of the spa-pool overflow.

I was in the pool yesterday and used my thumbnail to scrap a bit of it. Some came off, some didn't....In one of my other pools about 20 years ago I remember being a little to aggressive with the acid and repeated cleanings....as scrubbing with a brush didn't work...and yes I took a little of the grout out too...which was a bummer. Since we just re-tiled the pool last year. I wanted to keep it "new" as possible. I'll start with 25% acid and work my way up. Thanks for the replies.