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!