Clean Tile Grout

[millargs888]

Hi Everyone, my name is Gordon, I'm new to Trouble Free Pool, I'm also a new pool owner.
My problem is the discolouration of the grout between my pool tiles.
I use a skimmer based suction unit, with brush attachments, that doesn't seem to remove the stains.
I use a Dolphin robotic clearer, with a rotational scrubbing brush, that doesn't seem to remove the stains.
I have drained the pool and scrubbed with bleach, and also with muratic acid.
Both remove a little of the staining but the stains still remain.
Is there anything that I can use to remove these grout stains, or is there a paint, or a lacquer that I can use to cover the grout ?
Any help would be appreciated.

 

[duraleigh]

Welcome to the forum
Muriatic acid followed with bleach is your best option. You may not get it all but I think you can get most with reated applications.

How strong is the dilution of muriatic you are using? Does it "foam" when you apply it?

 

[millargs888]

Welcome to the forum
Muriatic acid followed with bleach is your best option. You may not get it all but I think you can get most with reated applications.

How strong is the dilution of muriatic you are using? Does it "foam" when you apply it?

Dave, thank you for the response.
The muriatic acid I am using is 29%, and yes it foams when I apply it.

 

[duraleigh]

Are you diluting the muriatic? Usually about 2:1 water and muriatic.

After the muriatic treatment submerge the affected grout and elevate you FC to twice it's normal level and , over time, the staining will likely go away.

Can you post test results?

 

[millargs888]

Are you diluting the muriatic? Usually about 2:1 water and muriatic.

After the muriatic treatment submerge the affected grout and elevate you FC to twice it's normal level and , over time, the staining will likely go away.

Can you post test results?

Apologies for the late reply.
I haven't been diluting the acid, I have used it straight from the bottle, taking the usual precautions.

I am waiting for a replacement bulb at the moment, when I have that I will drain the pool and try your recommended treatment.
I will post results when I have them.
Many thanks for the help.

 

[igneous]

The stains may be calcium deposits that have layered over time from having pH too high. I just inherited a pool with bad calcium deposits and have been chiseling them off....muratic acid did nothing.
I'm going to make a soda blaster and use baking soda to get the waterline marks off, maybe it will also work for the super hard calcium.

 

[millargs888]

Dave,
Sorry for the long delay in replying.
I did as you suggested.
Cleaned with diluted muratic acid, then scrubbed again with bleach.
It did remove many of the stains, however, I now find I have white/light gray stains on the middle of some of the tiles.
I have a suspicion that the tiles used may not have been of the best quality.
I think that the muratic, or the bleach, or both have etched into the tiles through a poor glaze.
It may also be as "igneous" has mentioned above, and been some calcium deposits, although I have tried to keep the pH levels well within bounds.
With the amount of heat and sunshine that we get here in the Philippines, both the acid and the chlorine tend to burn off quite quickly.
Thanks for your help.