Brown spots on bottom of pool after switching to SWG

[jkbk223]

Hi,
We have Brown spots on bottom of pool after switching to SWG summer of 2022. We also had the plaster redone in fall of 2021. Does the cheaper salt at Walmart vs pool store contain metals? Is there anything I can add daily or weekly to keep the metal from staining the plaster? Pool chemistry is Free Chlorine 5.35, Total chlorine 5.35, PH 7.5, TA 71, Calcium 347, CYA 42, IRON 0, Copper .1, Phosphates 215, salt 4000.
Thanks in advance,
Barb

 

[Texas Splash]

It could be from the salt. Some batches just have a few more impurities. Have you tried rubbing the spots with a Vitamin C tablet?

 

[jkbk223]

It could be from the salt. Some batches just have a few more impurities. Have you tried rubbing the spots with a Vitamin C tablet?

I have not. I have tried a pumice stone but cannot get them out. I will try Vitamin C. Do you recommend a type of salt that may have no minerals in it?

 

[mknauss]

Do you recommend a type of salt that may have no minerals in it?

Salt - Further Reading

www.troublefreepool.com

 

[Texas Splash]

Do you recommend a type of salt that may have no minerals in it?

While some have reported on & off issues with water softener salt, I've not had any problems. But as of late I now use solar sale.