Unidentified Pool Stain

[KellyS.2010]

I have a person I work for as a personal assistant. She has a 25,000 gal chlorine pool with some dark stains that popped up about a year ago. She says she has had pool people come out and they just say they don't know what it is. We performed one of those Jack's Stain ID kits and got no results from any of it. So we are working to try and identify what this is. We are open to suggestions on how to figure out what stain this is. Located in Dallas, TX.

 

[Texas Splash]

That discoloration looks like organic staining or possibly calcium staining. In some cases a little of both. Without knowing the true history of the pool's chemistry validated by accurate test results from a TF-100 or Taylor K-2006C it's anyone's guess.

 

[KellyS.2010]

Here are the test results I recorded from her water today. But I understand more information is needed. She has been taking her water to Leslie's to get tested and her results have been all over the map. Is there a way to verify if it's an organic stain? I assume that would mean algae and that a SLAM would be needed?

 

[wireform]

She has been taking her water to Leslie's to get tested and her results have been all over the map

That's part of the issue right there

 

[KellyS.2010]

That's part of the issue right there

I know, I'm trying to teach her new ways but I can only do so much.

 

[Texas Splash]

Is there a way to verify if it's an organic stain?

You could rub a chlorine tablet on a stained area for a few minutes. Don't just leave it in one spot though or you risk making a bleached circle spot. Move it around slowly. Or, if either of you have some cal-hypo granules, sprinkle some on a stained area as a test.

 

[KellyS.2010]

You could rub a chlorine tablet on a stained area for a few minutes. Don't just leave it in one spot though or you risk making a bleached circle spot. Move it around slowly. Or, if either of you have some cal-hypo granules, sprinkle some on a stained area as a test.

Okay, I just called her to try it and she said the chlorine tablet worked.

 

[Texas Splash]

Okay, I just called her to try it and she said the chlorine tablet worked.

Wow. That was fast. In the dark no less. Ha. Okay, so she definitely has organic staining at a minimum. Now being a TFP member, you probably know that organic staining is a result of pool chlorination at some point and perhaps previous bouts with algae that went so long it stained the surface. A SLAM Process would probably be a good starting point, and once the water is confirmed as crystal clear, next to no CCs, and passing the Overnight Chlorine Loss Test, the next step could be maintaining a slight elevated FC level for her CYA. That could take a few days or a few week with consistent brushing to help cut through the staining. Hard for us to tell. But at least you know part of the equation - organic staining.

 

[KellyS.2010]

Wow. That was fast. In the dark no less. Ha. Okay, so she definitely has organic staining at a minimum. Now being a TFP member, you probably know that organic staining is a result of pool chlorination at some point and perhaps previous bouts with algae that went so long it stained the surface. A SLAM Process would probably be a good starting point, and once the water is confirmed as crystal clear, next to no CCs, and passing the Overnight Chlorine Loss Test, the next step could be maintaining a slight elevated FC level for her CYA. That could take a few days or a few week with consistent brushing to help cut through the staining. Hard for us to tell. But at least you know part of the equation - organic staining.

Thank you so much! I'll share this info and see how it goes!

 

[KellyS.2010]

Okay, it has been a while since posting here. But we have been slamming the pool for about a week and a half. Now, keep in mind that this is at my employers house and I don't live there. So measurements and chlorine additionsnhave been happening at morning and late afternoon on the days where I can actually be there. (I attempted to teach her how to test the water herself but she just could not get it) So the pool improved a bit but it seems to have just stopped getting better. It has looked the exact same for days. And this blotchy staining she said had started about 4 years ago and has just been slowly progressing. So I guess I'm just wondering if algae can leave permanent stains if left too long? Or if it could be something else? Or am I too impatient and just need to keep going?

 

[Texas Splash]

It's possible that there is some organic staining coupled with calcium scale on those steps. That will give the appearance of a dingy off-white stain that is difficult to remove. Poor chemistry over a long period of time is to blame. Not much you can do in this scenario if the owner isn't willing or capable to testing on their own consistently.