Closing and Metal Stain

Tired_Pool_Owner

New member
Oct 18, 2019
3
South Dakota
Hello -
Long time reader and first time poster.
This summer I was alerted to a pool stain that came from my shock. It is a metal stain and I have battled on and off with adding stain remover once my chlorine was near 0. It has had mixed results as you can see from the images.
I am closing the pool in a couple of weeks and wondered if it made sense to add more stain remover to the pool and have it circulate for a bit now, or, when we open the pool in the summer.
See images and please advise. I have been fighting with this stain for a few months now.
Stain remover: Amazon.com : Essential Values 2 Pack Swimming Pool & Spa Stain Remover (4 LBS Total) - Natural & Safe, Works for Vinyl Liners, Fiberglass, Metals - Removes Rust & Other Tough Stains Without Harsh Chemicals : Garden & Outdoor
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Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome! :wave: Much of what you are asking depends on several factors. After all, treating with a stain remover won't do much if the metal content or reason for staining is still there. So here are some things to consider:
1 - Where is the source of staining coming from? Do you fill from a well (iron), or have you used pool store chlorinating products and algaecides that contain copper?
2- Have you tested those stains to confirm if they are iron (Vitamin C tablet), copper (rubbing dry acid in a sock), etc?
3 - What are your current test results from either a TF-100 or Taylor K-2006C. We know if the pH and/or FC are not controlled it can increase staining.
4 - If clean, non-metal water is not an option, your best and most reliable method of metals management is to add sequestrant to the water and replenish it periodically. Sequestrant is a chemical that binds to the iron in the water so that it can't form stains or turn brown. Sequestrant breaks down slowly, so you need to add more regularly. ProTeam's Metal Magic and Jack's Magic the Pink Stuff (regular), the Blue Stuff (fresh plaster), and the Purple Stuff (SWG) are some of the top sequestrants. You can also find other brands with similar products, some of which are noticeably less expensive. Sequestrants based on HEDP, phosphonic acid, or phosphonic acid derivatives are the most effective.
5 - Don't forget to update your signature with all of your pool and equipment info. It helps.
 

Tired_Pool_Owner

New member
Oct 18, 2019
3
South Dakota
Thank you Texas Splash, I appreciate your thorough response. In answer to your questions:
1 - We were using the clorox shock treatment, and found that there was copper in it and that lead to the staining.
2 - Yes, the small parts of the liner that you see were areas where I had gotten some of the abscorbic acid down to the bottom of the pool. As you can see, it needed more than I had to provide.
3 - I do not have one of those testers yet, I think I may grab one in the winter (our off season). I can tell you that PH has been rather low lately and chlorine is high on my test strips.
4 - Would it possibly be best to try the sequestrant right at the beginning of next season? Perhaps I can hit that hard in the early spring to see if I can lift that stain away? Or in this case, since it has been on there some time, is the acid the better approach? I just realized our pool company is closing the pool tomorrow. Whoops.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
You're in a bit of a pickle with closing scheduled for tomorrow. You'll have to make-due I suppose and tackle everything next spring as soon as possible. If that's the case, consider the following:
1 - Dump the test strips and get a TF-100 test kit - include the magnetic speedstir if you can. You really need the accurate testing.
2 - Add some sequestrant now if you can, and if you have access to the water over the winter, perhaps a 2nd round mid-way through and stir it around manually.
3 - Between closing and the winter season, you may change some water. That's good to help remove some copper. Consider changing as much water as possible betwen now and next spring to lower the copper content as much as possible before tackling stains.
4 - Next spring, do an AA treatment if the staining is wide-spread and stick to regular bleach/liquid chlorine for your FC level. Stay away from Clorox brands and anything that says splashless or scented. I often go to Home Depot a lot for their pool chlorine (10%).

Good luck tomorrow and we'll see you next season. :swim: