White stain on tile

[drewgost]

Good morning,

I have a new pool from mid 2017, Gunite pool installation. We noticed this year a lot of white stains on the tile and wa wondering if anyone new what to use safely to clean them?

Thanks,

Drew

View attachment 80082

 

[Texas Splash]

Looks like it could be calcium. For that, we generally recommend starting with the most mild, non-abrasive methods first. Below are some examples (I may have missed some):
- 4:1 ratio of water and muriatic acid then scrub with a brush (nylon first then perhaps steel)
- Magic Eraser or similar product
- Some 1500 grit wet/dry
- Pumice stone

Again, with all of those, be careful and try a small discrete area first. Each pool, tile, and stone surface is different, so no one method is perfect for the other.

 

[Killer95Stang]

Pumice has worked for me in the past. As far as the stain forming, I would check your water chemistry. If you have real hard fill water, or high Calcium in your water, you need to run your PH on the lower side 7.2 - 7.5 to keep that from forming in the future.

I have hard water and our Ch level is up to 900 where I live, but I'm able to keep the CH deposits at bay with careful PH monitoring.

 

[drewgost]

thanks for the tips I will try the pumice stone and get PH on the lower side.
This is the best forum ever

Drew

 

[dice7074]

I have the same hard water issue... My CH is at 600, so I'm trying to keep my pH around 7.3 - 7.4.

With that said... my Calcium buildup was so thick, a pumice stone barely scratched the surface... I ended up using a hammer and it worked wonders. It didn't even damage my tiles... Check this link out...

HOW TO: Remove YEARS of calcium mineral deposit build up on the side of your swimming pool! - YouTube

 

[drewgost]

Dice I dont think mine is Calcium buildup being it is on the coping as well as the tile, people are mentioning Efflorescence? I don't know if that is the same but I am nervous to take a hammer at this time. But thanks for the link I will save it for the future

 

[dice7074]

LOL... taking a hammer to my pool was a very gutsy move on my part... I don't blame you for being nervous or not wanting to try it, but it worked so well, I had to share! And yes, to my knowledge efflorescence is the process of calcium salt - in this case CaOH2 (calcium hydroxide) being dissolved in water and migrating to the surface. When water evaporates, the calcium crystals mix with the CO2 in the air and form calcium carbonate (CaCO3) - the white stuff you're seeing on your tile.

 

[tstex]

Dice I dont think mine is Calcium buildup being it is on the coping as well as the tile, people are mentioning Efflorescence? I don't know if that is the same but I am nervous to take a hammer at this time. But thanks for the link I will save it for the future

Drew,

What type of stone is your coping? has it been sealed? If not sealed and you have had a lot of rain, big rain at one time, it is efflorescence. Also, calcium doesn't just form in random places w out contact from of constant water source being in contact w the tile/substrate. Calcium build-up forms on tile water lines, spillovers and similar.

Next, what type of pool testing kits or methods are you using? what is your CH [Calcium Hardness] ?

Post back w these answers. But, if it's efflorescence, you will need to go the route of a very, very fine wetted sand paper ...the sooner the better.

Good luck, tstex

Also, if your tile is something like travertine or a softer stone, DO NOT use any form of acid, it will destroy it.

 

[drewgost]

Hi tstex,

Thanks for the information.
My coping is Techo-Block bullnose grande coping. So you are saying because this appears to be (splashing instead of a water line) most likely Not Calcium.
As far as testing I just received the TF-100 kit from TFTestKits.net. I will be testing the water today and report back.
The tile is ceramic frost proof

 

[drewgost]

So I just completed the TF-100 test and I am a little confused here is what I have: Calcium Hardness CH is 400 I have to go read why that seems high to me.
The pool company came out for some minor issues and he told me to use DuPont StoneTech Professional Concentrate Restore Acidic Cleaner http://www2.dupont.com/Products_and_Services/en_AU/assets/downloads/dcse msds/Restore.pdf
I will try this later today or tomorrow and get back to you with results.

 

[steinre1]

The first response is correct. Just mix some muriatic acid and water in a handheld spray pump and spray it. You'll immediate know if it is working if it starts to fizzle. Easy and cheap. Can't hurt anything and you can always use the muriatic acid later for pH purposes.