Plenty of ways to waste money in this hobby …. buying a premium salt is one of them (in my opinion). I have never found the choice of salt to be a driver of success or failure, particularly if you dose or use a CaRx, so I go with the least expensive credible option = IO. I know people can get all hung up over precise levels of this and that , and if that's your thing then so be it. It's not mine.