Stains from pool salt!!!!!! I am not happy!

[waterbear]

I was at a local pool store and I bought a bag of salt for my saltwater generator. It was twice what I normally pay at the grocery store for Morton Pool Salt, which is one of the salts I normally use. It was more of a convenience thing at the time to get it at the pool store. I have a fiberglass pool and normally pour the salt on the ledge near the steps since my return is aimed to flow over it and it helps to dissolve the salt quickly. I put the salt in 2 days ago and today I was doing my weekly pool maintenance and I notices that the ledge and the steps where I poured the salt were stained with a yellowish, light brown stain that looks like iron to me! The expensive pool salt was very free flowing small crystals like table salt, even smaller than the Morton and Diamond Crystal pool salt I normally use. I suspect it might have an anti-caking compound in it like prussiate of soda, which is an iron compound (sodiium ferrocyanate)! There was no mention of anything on the bag! It just said 99.5% pure! This is the first time I have ever had staining from salt (I have used plain water softenter pellets, solar salt and Morton and Diamond Crystal Pool salt in the past)
Tomorrow after work I am stopping at the drugstore for some vitamin C tablets to see if the stain is iron! If it is I guess I need to order some ascorbic acid and get a few bottles of sequesterant now! I am NOT a happy camper. Can't believe that I got pool stored! I had never heard of this brand, it was not Morton or Diamond Crystal and I threw out the bag so I can't remember the name but it was labeled as pool salt for salt water genterators! Next time I need salt I will either stop at the grocery store for a bag or Morton or drive all the way to the store where I work for a bag of Diamond Crystal!

[mbar]

That is really rotten! I would try lowering the ph down to 7, and add the sequesterant first - sometimes you can lift the stain off this way, if it doesn't come off you can then to the ascorbic acid routine. You didn't get pool stored, you just got tricked because there was no mention of anything on the bag but salt.

[waterbear]

That is really rotten! I would try lowering the ph down to 7, and add the sequesterant first - sometimes you can lift the stain off this way, if it doesn't come off you can then to the ascorbic acid routine. You didn't get pool stored, you just got tricked because there was no mention of anything on the bag but salt.

Yes, but I usually don't buy my salt at the pool store! Not even at the one I work at because I can get salt much cheaper at the grocery store! Gonna pick up a few bottles of Purple Stuff or Metal Magic tomorrow at work and take it from there.
Already got my pH down to 7.2 in anticipation of it! Gonna test with a vitamin c first just to make sure it's iron.

[Jeffski]

With a SWG you dump salt straight into the pool? How often do you do this?

[waterbear]

I add salt whenever my salt level drops below about 2800-3000 ppm. Normal maintenance for a SWG. I have a leak in my spa that the builder hasn't fixed yet so I am having to add salt a bit more often than normally.

[tonyl]

I've had staining from solar salt crystals (Morton...99.5% pure) too Evan. The first or second year I just dumped a couple bags in several spots without moving them around. The old liner was faded so it was pretty apparent but lightened over time. Before the forum crashed, I think Pat posted he had staining as well and uses salt blocks.

Next time you might try moving around with your brush in several places.