As I search, there are different recommendations: every year, every 2 or 3 years, every 5, never. I suspect the median actual as-done interval would be higher.
It seems to me that the reasonable interval would be better expressed in terms of bags of salt and what kind of salt it is. I tried doing some calculation. Morton solar salt says "Morton® Solar Salt is 99.7% pure salt harvested from natural salt brine through solar evaporation." I figure that much of the not-salt stuff is water soluble (or forms a suspension), so I arbitrarily chose 99.9% soluble or suspended-- 0.1% estimated residue. If I very arbitrarily pick 1 lb of debris in my tank at cleaning, that would call for a cleaning every 25 40-pound bags.
For my rough calculations, I arbitrarily picked 18 grains of hardness, 6 pounds of salt/cubic ft of resin, giving 185 gallons of softened water per pound of salt.
At 60 gallons softened per day, that would suggest cleaning every 8.6 years. Two people totaling 120 gallons per day: half that and so forth.
I use Morton System Saver pellets mostly. They have even less insolubles than their solar salt. They also contain a citric acid additive, which is very soluble. Iron in the fill water would make more frequent cleanings warranted.
Remember these numbers are estimated and/or arbitrary, and I may have made a calculation mistake. I think my numbers are reasonable.
It seems to me that the reasonable interval would be better expressed in terms of bags of salt and what kind of salt it is. I tried doing some calculation. Morton solar salt says "Morton® Solar Salt is 99.7% pure salt harvested from natural salt brine through solar evaporation." I figure that much of the not-salt stuff is water soluble (or forms a suspension), so I arbitrarily chose 99.9% soluble or suspended-- 0.1% estimated residue. If I very arbitrarily pick 1 lb of debris in my tank at cleaning, that would call for a cleaning every 25 40-pound bags.
For my rough calculations, I arbitrarily picked 18 grains of hardness, 6 pounds of salt/cubic ft of resin, giving 185 gallons of softened water per pound of salt.
At 60 gallons softened per day, that would suggest cleaning every 8.6 years. Two people totaling 120 gallons per day: half that and so forth.
I use Morton System Saver pellets mostly. They have even less insolubles than their solar salt. They also contain a citric acid additive, which is very soluble. Iron in the fill water would make more frequent cleanings warranted.
Remember these numbers are estimated and/or arbitrary, and I may have made a calculation mistake. I think my numbers are reasonable.
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