White plaster turning grey? Help!

_scouter_

Member
Jun 21, 2009
11
I am still trying to get the hang of keeping all my levels in check, and just when I think I have a handle on it, a new issue has appeared. I have included pics in hopes that someone can identify my problem.

Specs:
25,000 gal, SWG, gunite pool (only a year and a half old)
pH 7.2-8.0 (fighting to keep it down since the beginning, but not as bad lately)
Free Chlorine 3-5ppm
TA 80-100ppm
CYA 30-50ppm
Salt 3200 ppm

Our plaster is white and I had noticed some greyish splotchy, swirly markings in the bottom, but not very dark or noticeable. Lately, it has become more pronounced and widespread. Some rust looking spots in places appeared overnight as well. We have had some black algae problems which we are still fighting somewhat, but hasn't been a big issue and mostly a problem in grout of the tile and in corners of the steps. My levels all seem to be good according to my test strips (and pool store didn't find anything out of balance either when I brought in a sample). Any advice is welcome. We are about to be out of town for a week and want to try and nip this before we leave. Thanks![attachment=1:1ng0y0bg]photo.JPG[/attachment:1ng0y0bg][attachment=0:1ng0y0bg]photo2.JPG[/attachment:1ng0y0bg]
 

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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,396
San Dimas, CA (LA County)
It looks remarkably like the calcium scaling in my pool!

You'd think it would be as white as a movie star's teeth, but it's sort of a blue-gray, and irregular. Splotchy.

Your test results left off Calcium Hardness, CH. That's sorta critical to know. You really ought to buy a first-rate test kit and then you can punch the numbers into Pool calculator and see if you're in danger of scaling. Or if you have the CSI below zero, where, over several months, you can actually start dissolving some of that scale back into solution. Takes a lot of elbow grease, too.
 

_scouter_

Member
Jun 21, 2009
11
My current test strips do not have a measure for CH on them, but I guess I assumed the pool store was testing for any and all levels that could create problems. This sounds like it could definitely be the problem since I haven't kept an eye on Calcium levels. I will stop and pick up strips that will give me an idea of where that level stands and the right 'stuff' to fix it if that is indeed the problem. I need to invest in a good test kit, but time is short until we leave for vacation. So are you saying that if that is the problem that I can fix it over time with getting the calcium levels right, and I imagine some pool scrubbing?? I can reverse the damage and replace the calcium into the plaster???

Thanks so much for your advice, and so quickly!!
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,396
San Dimas, CA (LA County)
_scouter_ said:
My current test strips do not have a measure for CH on them, but I guess I assumed the pool store was testing for any and all levels that could create problems. This sounds like it could definitely be the problem since I haven't kept an eye on Calcium levels. I will stop and pick up strips that will give me an idea of where that level stands and the right 'stuff' to fix it if that is indeed the problem. I need to invest in a good test kit, but time is short until we leave for vacation. So are you saying that if that is the problem that I can fix it over time with getting the calcium levels right, and I imagine some pool scrubbing?? I can reverse the damage and replace the calcium into the plaster???

Thanks so much for your advice, and so quickly!!
Over a loooooong period of time, you can reduce the scaling. An acid wash or sandblasting would be faster and more complete. And more expensive. And no, it doesn't put calcium back into the plaster. The calcium may come partially from curing plaster, but usually from hard water. Do you get crust on your shower head and scale rings at the water line in your toilet? I do.
 

cbad

Member
Jul 13, 2010
12
_scouter_ said:
My current test strips do not have a measure for CH on them, but I guess I assumed the pool store was testing for any and all levels that could create problems
This is part of the problem, but not a unique one. Pool stores are not the greatest source of accurate information. I think Richard was suggesting getting a good test kit, like the Taylor k-2006 or the TF-100, and learn to test yourself. It's really pretty easy, and after a while maintaining your water in great condition will be second nature. Plus you'll save a lot of money buying only the stuff you really need, and not all the stuff the pool store recommends.

Here's a link to test kit info:

pool-school/pool_test_kit_comparison

Good luck!
 

_scouter_

Member
Jun 21, 2009
11
Yeah that is the main drain and the other item in the picture is the tail of our Polaris. I called the pool store today to check our Calcium level data for the numerous times I have been there to get our water checked. As of July 10th it was at 300 ppm, which I know is a little high but wouldn't think it is the cause. She said it has never been way out of line. I called another pool store/company that specializes in gunite pools which my regular pool store lady recommended to speak with about the issue. I explained the situation and her suggestion was that the plaster itself might be the root cause if all the levels are checking out okay. She said that the original calcium level in the plaster might be causing the etching/pitting especially if it was done in cold weather, which it was. I have put in a call to the folks who put the pool in but have not gotten a call back yet.

I have been shocking the pool with 2 pounds of shock to clear up the black algae (with scrubbing). Any other comments/suggestions to get to the root of this mysterious grey mess is appreciated.
 

_scouter_

Member
Jun 21, 2009
11
Just got off the phone with a pool guy who several people recommended. He suggested putting a chlorine tablet on one of the rusty looking spots overnight to make sure it isn't algae. Next use some ''metal out'' since our area has metals in the water. He said if that didn't work, then it is most likely a problem with the Salt system not being grounded. The fix for that is supposed to be grounding it ($250) and that the only way to get the existing damage out is to replaster.

Any feedback on this advice???? We leave Sat for vacation - so unless someone advises me differently, I guess I will go with this plan. Still waiting for a call back from the guys who put the pool in.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
Nothing you have said indicated any need to re-plaster. Nor does grounding the SWG make any sense (it should already be grounded, but even if it wasn't that wouldn't cause stains).

There are still several possibilities of what the stains might be: algae, iron, copper, organic stains, etc. I haven't followed the whole discussion. Have you tried feeling the stains, do they feel smooth, rough, or slimy? Have you tried holding a vitamin C tablet to a stained area for 30 seconds? Have you tried holding a trichlor tablet up to a stained area for one minute?
 

_scouter_

Member
Jun 21, 2009
11
I did put a chlorine tablet on one of the rusty spots overnight and it didn't look any different in the morning. Tried scrubbing with it as well and that didn't work either. I put some 'metal out' in later this evening and will check tomorrow to see if I get any improvement. Haven't tried the vitamin C tablet yet. The stains are somewhat embedded in the natural crevices of the plaster and don't really feel any different than non affected parts of the pool.

One of the guys who put the pool in contacted me today and is going to come with another "knowledgeable" guy next week to check it out and see if they can diagnose the problem. Thanks for all your responses to my problem!!
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
Definitely try the vitamin C tablet held against a stained area test. Your description so far has ruled out algae and organic staining. Iron and copper stains are now the two leading candidates. Vitamin C will remove, or at least noticeably reduce, iron staining, which is the most likely possibility at this point.
 

geekgranny

LifeTime Supporter
Aug 20, 2009
1,358
North Central Texas
Have you been using any products that have copper in them? Many products do. Many HTH chlorine type products contain copper. Many algaecides contain copper. They will cause staining that is nearly impossible to remove unless you do an acid wash. How old is the finish on the pool. Have you ever used any ionization products like Nature 2 or Floatron? They both release copper.

Have you had your pool tested for metals?

gg=alice
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
Could it be that anyone has spread Ironite or any fertilizer containing iron such that it could have gotten into the pool?
 

geekgranny

LifeTime Supporter
Aug 20, 2009
1,358
North Central Texas
anonapersona said:
Could it be that anyone has spread Ironite or any fertilizer containing iron such that it could have gotten into the pool?
Here's hoping it is iron. Ascorbic Acid treatment will take care of that. Vit C tab test will tell. Be sure to get uncoated, non fancy Vit tabs. Ester Vet C won't work as the acid is "buffered" or such. They just form a yellow blob and the yellow has to be scrubbed off. Been there; done that.

Edit Iron has an affinity for scale. Even if calcium levels are not "way over the top" extended periods of high pH and/or high TA can lead to calcium scaling. That's why is is so important to keep on top of all values. In my pool the iron stains the calcium scale much more so than the plaster; copper attaches mostly to the plaster. My plaster is blue so it is easy to see. Calcium scaling can be reduced over time keeping certain type of sequestrant in at all times, pH no higher than 7.2, and brushing. I'm in that process right now. At times the pool will cloud up adding certain things to the water, and, yes, it takes time to filter it out, but if all other things are kept in constant balance, you will know why the water is clouding, and you can continue to use the pool.

My fill water is not high in iron but the sand/silt/clay/fine dust, that is constantly carried or blown in the pool, contains iron. The calcium scaling on the bottom of shallow end, where most of the dust settles for a few hours a day, between the 2 or 3 Aquabot runs per 24 hours, will get a slight tan tinge if I let the pH go even a little above 7.2. My calcium scaling has been slowly releasing since last fall and is noticeably less than it was just a few months ago.

gg=alice
 

_scouter_

Member
Jun 21, 2009
11
Well I tried the vitamin c tablet idea (accidentally got Orange ones) and definitely had a impact on some of the rust colored stains that I could easily reach but not on all. Seem to have new ones showing up daily through Saturday which is the day we left for vacation. Metal out doesn't seem to be getting rid of grey stuff yet but hoping to see a difference when we return home. We have fought high ph for the first year (pool is only 1-1/2 yrsold). Need to try and get to the bottom of both problems soon hopefully. Will do a test for other metals when I return and maybe get some stain out. I have shocked the pool with shock n swim types products. Is that HTH products referred to earlier?
 

geekgranny

LifeTime Supporter
Aug 20, 2009
1,358
North Central Texas
_scouter_ said:
Well I tried the vitamin c tablet idea (accidentally got Orange ones) and definitely had a impact on some of the rust colored stains that I could easily reach but not on all. Seem to have new ones showing up daily through Saturday which is the day we left for vacation. Metal out doesn't seem to be getting rid of grey stuff yet but hoping to see a difference when we return home. We have fought high ph for the first year (pool is only 1-1/2 yr old). Need to try and get to the bottom of both problems soon hopefully. Will do a test for other metals when I return and maybe get some stain out. I have shocked the pool with shock n swim types products. Is that HTH products referred to earlier?
When I was testing with Vit C tabs, last fall before the AA treatment, I had to leave them on certain spots for 20-30 minutes before I saw any change. Some areas didn't react very much to the Vit tabs but did lift when I did the AA treatment.

The only way to know for sure about copper in products is to have access to the specific label on each product. As of this year, all of the HTH products I've looked at, granular and tabs, have copper, no matter the store. I'm not sure about HTH cal hypo though. Many algaecides have copper too.

On a positive note, the process and product (HTH Metal Out, maybe Metal Control) I'm using to keep iron staining at bay, and slowly release the calcium, is, to my eye maybe lightening the copper stains. The cloudier your water the better the copper stains are hidden. :roll: Another way to "hide" the copper stains, especially if your water is very sparkly, is to keep some turbulence on the surface. That way the sun reflecting all around, on surface and light patterns on pool bottom and sides, disguises them somewhat. :mrgreen: In a clear, still pool they are most noticeable. They don't show as well at night, with the LED color changing light. The medium blue color is great for disguise.

If my copper stains are lightening it will be years before they release totally, if at all. I can't acid wash as my 14 yr old, still in good shape, plaster has been acid washed three times. Too risky to do it again.

gg=alice
 

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