I live in Australia, the pool market here is a little different to the US, different stores and brands. So this is to assist the Aussie TFP contingent as I'm sure some of them will have been told this story too.
So I needed to add a couple of bags of salt to the pool and I was over at Bunnings anyway and picked up a couple of bags of their Sunray premium salt. I happened to run into a freind who works in the pool industry and he promptly trotted out the old story about how I should buy it at the pool shop because the Bunnings stuff is cheap and nasty and is the first scrape off the salt pans and full of impurities and it will stain the pool and leave insoluble residues and so on.
So, is it true ? Short answer, no, it's not. It's utter bunkum.
So working in the chemical industry, I have spent decades assessing raw materials and looking at product specifications. So given that salt is a low cost commodity chemical, it doesn't typically pay to ship it internationally if it's locally available. The freight costs soon get bigger than the value of the product. So I suspected that Bunnings are sourcing locally. A quick google for Sunray salt specification found that it is indeed made locally by Cheetham Salt who are a company I have sourced raw materials from in the past and found to be a reliable supplier with good quality control.
There are two grades of the Sunray brand salt, regular and premium. The local pool shop sells the Mermaid brand. Guess what, that's also a Cheetham product and is made to similar specs to the Sunray premium brand from Bunnings. They're all refined salts, all 99.4 % pure. The regular Sunray brand has a slightly coarser particle size, a slightly higher moisture content and contains up to 2.5g/kg sulfate. The Mermaid brand is finer particle size and lower moisture content but also lists up to 2.5g/kg sulfate on the specification. The Sunray premium product spec, is also nice and fine with a low moisture spec and the spec does not list that 2.5 g/kg of sulfate. So the Bunnings premium product looks like it's actually more highly refined and better quality than the pool shop's Mermaid brand. I try not to add sulfate to the pool if I don't need to. 2.5g/kg in the salt is not a big deal, but it doesn't go away, except by dilution with fresh water. There is potential for it to build up over time and it's not particularly good for many pool surfaces or equipment if it is allowed to build up to high concentrations.
Cheetham also make the Ocean Ultra Fine Pool salt grade, which is a very fine particle size with no sulfate on it's specs but due to the fine particle size it contains potassium ferrocyanide as an anticaking agent which I would prefer to avoid as well. I'd rather sweep the salt around for a few minutes more than add an anticaking agent.
My other local pool shop, Poolwerx only sell their own brand of Salt, prepared to bet that it's a locally sourced product too but they don't have a specification for it on their web site, so it's impossible to know what quality it actually is.
So I needed to add a couple of bags of salt to the pool and I was over at Bunnings anyway and picked up a couple of bags of their Sunray premium salt. I happened to run into a freind who works in the pool industry and he promptly trotted out the old story about how I should buy it at the pool shop because the Bunnings stuff is cheap and nasty and is the first scrape off the salt pans and full of impurities and it will stain the pool and leave insoluble residues and so on.
So, is it true ? Short answer, no, it's not. It's utter bunkum.
So working in the chemical industry, I have spent decades assessing raw materials and looking at product specifications. So given that salt is a low cost commodity chemical, it doesn't typically pay to ship it internationally if it's locally available. The freight costs soon get bigger than the value of the product. So I suspected that Bunnings are sourcing locally. A quick google for Sunray salt specification found that it is indeed made locally by Cheetham Salt who are a company I have sourced raw materials from in the past and found to be a reliable supplier with good quality control.
There are two grades of the Sunray brand salt, regular and premium. The local pool shop sells the Mermaid brand. Guess what, that's also a Cheetham product and is made to similar specs to the Sunray premium brand from Bunnings. They're all refined salts, all 99.4 % pure. The regular Sunray brand has a slightly coarser particle size, a slightly higher moisture content and contains up to 2.5g/kg sulfate. The Mermaid brand is finer particle size and lower moisture content but also lists up to 2.5g/kg sulfate on the specification. The Sunray premium product spec, is also nice and fine with a low moisture spec and the spec does not list that 2.5 g/kg of sulfate. So the Bunnings premium product looks like it's actually more highly refined and better quality than the pool shop's Mermaid brand. I try not to add sulfate to the pool if I don't need to. 2.5g/kg in the salt is not a big deal, but it doesn't go away, except by dilution with fresh water. There is potential for it to build up over time and it's not particularly good for many pool surfaces or equipment if it is allowed to build up to high concentrations.
Cheetham also make the Ocean Ultra Fine Pool salt grade, which is a very fine particle size with no sulfate on it's specs but due to the fine particle size it contains potassium ferrocyanide as an anticaking agent which I would prefer to avoid as well. I'd rather sweep the salt around for a few minutes more than add an anticaking agent.
My other local pool shop, Poolwerx only sell their own brand of Salt, prepared to bet that it's a locally sourced product too but they don't have a specification for it on their web site, so it's impossible to know what quality it actually is.
