From time to time I get crazy ideas, and I wanted to run this past those who probably know more about the subject than I. I live in lovely S. California where the calcium hardness is 340 right out of the tap. Obviously I am trying to control my CSI to ensure that scaling will not happen for some time, but it occurred to me that although reverse osmosis or replacing water are both fine ways to control CH, a water softener hooked up to a submersible pump might just suck the calcium right out of the water. My understanding of how it works is that the calcium & magnesium in the water would be replaced by sodium when it is run through the filter resin. I assume that I would have to leave the device hooked up for about a week or more to reduce the CH to an acceptable level. After that, I could hook up the water softener to the main line in the house and then every time I refill the pool, it will be with "soft water". I doubt it would eliminate the calcium issue entirely, but I bet I would be able to go much longer without having to drain the pool.
My concern is that too much sodium in the water might be just as bad as too much calcium. does anyone have any thoughts/experience they can share?