Light spots pebble tec

[jamie1983]

I have noticed large sections of light spots on my pool. I will try to get pictures up, but it's tough to see depending on clouds/shadows. What could be causing the spots? Ph and chlorine are in line, calcium hardness is 150, any advice would be appreciated.

When I scrub them nothing happens.

 

[JasonLion]

White spots are usually calcium scaling, though there are some less likely possibilities.

Please post a complete set of water test results and we can give you a better idea of what might actually be happening.

 

[jamie1983]

Will do

 

[jamie1983]

Fc- 5.0
Cc- .5
Tc- 5.5
Ph- 7.2
Ta- 30
Ch- 150
Cya- 0

 

[elwood58]

Your CH is pretty low. Should be at least 250. Unless your pool is indoors, you also need to get CYA up to 70. Low CH will leach hardness from your finish.

 

[jamie1983]

I will work on raising ch and cya this week, is it possible the low ch is causing the light spots?

 

[onBalance]

Consider this post as a possibility: white-spotting-of-new-plaster-pools-t56607.html

 

[jamie1983]

They are not small spots... They are large 4-5 foot areas that just look cleaner/lighter than the rest of the pool. But I scrub around them and nothing changes. I'm hoping the water warms up soon so I can jump in with a mask I and get a closer look. It makes no sense. There are 2-3 sections that are very noticeable.

 

[jamie1983]

The light spot is to the left of the vacuum

 

[onBalance]

Quartz or pebble? Date of plastering? Did you add a powdered chemical that sat on pool floor?

 

[jamie1983]

Plaster was done Dec 2011, it is pebble, that was my original thought, that it could be salt or something, but it is in areas that I never would have poured. No powdered chemicals added, only salt. Since I have noticed the spots and my CH was low I have added to raise CH, but other than that, nothing that would have sat.

It is in other spots, but between the clouds and reflection it is hard to see in pictures.

 

[onBalance]

Well, if not from salt addition, then could be from a botched acid treatment after plastering. The alkalinity is low and should be raised, but wouldn't cause localized areas to turn white. How soon after plastering did you notice the white areas? Could also be from different exposure of pebble versus cement.

 

[jamie1983]

I did not notice the discoloration until 2 weeks ago. That is why I was totally lost. I am hoping to get in the water in the next week or two and check it out up close. It's just too darn cold....You think the Ph would cause it....my Ph is normally 7.8 or so, but I added muriatic to get it down a little.

 

[onBalance]

No, the pH, TA, and CH isn't the issue. However, pouring undiluted acid in one spot could do it.

 

[jamie1983]

That may be the answer. How do you typically add acid? I was shown to walk it along edge and in front of returns... No real solution if that's the problem except acid wash then?? Its just cosmetic if that is the issue correct?

 

[onBalance]

If the white areas were caused by pouring in acid, then an acid wash won't work, but sanding with sandpaper might. If it happens to be a deposit of calcium, then an acid treatment would probably work. It is just cosmetic however.

For adding acid, dilute the acid in a bucket and either walk it around and slowly add it, or slowly pour over a return line when pump is on.