Salt Water Stains

rldaniel

Silver Supporter
Jun 18, 2020
13
Huntsville, Alabama
First posting. We gave up on our local pools stores this year and I bought a test kit and took over the maintenance myself. By reading through this site and following the recommendation, I felt like I had things under control. So much so, that I decided to switch the pool over to salt water. I installed a Circupool RJ60+ system earlier this week and followed the recommendation for chemistry. I am taking readings every three or four hours and am dialing in the %duty cycle on the SWG. My wife was not too excited about the switch, but I got her in the pool to prove to her it is not really that salty, and she immediately noticed the yellow staining in the steps. It was not there before, as my wife would have noticed. The skimmer basket is stained as well as the drain cover. All the exposed PVC (water return jets) are not stained.

After reading through the forums, I am wondering if it is iron? I am on city water and have never had this kind of problem before. If it is iron, the only way it could have gotten in the water was from the salt as the only other thing I have added is muriatic acid. I am trying to get my TA down from 90ppm and used muriatic acid to pull the ph down to 7.2 and aerate. Could the low ph cause this? Has anyone noticed this happening when converting to salt water.
 

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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,271
Tucson, AZ
It’s the Clorox pool salt. It has had reported problems in the past as it sometimes contains and iron based anti-caking agent.

You’ll need to treat for iron stains using an ascorbic acid treatment and sequestrant until rain water and splash out/refill dilutes enough of the iron away.

Sorry, but if you had asked, many would have warned you away from using Clorox products. I realize it’s easy to think that salt is just salt, but like almost anything pool related, it’s best to ask here first.

Good luck and enjoy the salt water pool.
 

rldaniel

Silver Supporter
Jun 18, 2020
13
Huntsville, Alabama
I just tried cleaning it with vitamin C crushed in a sock. I was amazed how easily it came off. No scrubbing required, just wipe it over and it is gone. Now to see how fast it comes back.....
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,271
Tucson, AZ
Definitely iron from the salt.

You can certainly use ascorbic acid to lift the stains but don’t be surprised if they return. If you need to do an AA stain treatment then sequestering agents will be needed to hold the iron in solution. Over time, rain and splash out will lower the iron levels.