R/O water system question

[Carolina girl]

I've got a serious "spotting" problem with my present GH water. I run misters a lot during the hot months, and my present shallow well water supply run through the misters deposits so much on the leaves that it isn't just unsightly, but must interfere with photosynthesis.

I have two water supply options, the shallow well and a deep well. The deep well water is very saline and very alkaline, known without an analysis that you cannot water plants with it, and better not use it to wash your car either. The shallow well water analysis shows TDS 205, SAR 0.6, pH 6.8, Ca 45.2, Fe 0.22, Mg 1.6, HCO3 2.3, SO4-S 4. The plants are doing very well using this for watering over the past 2.5 years. The problem is the deposits, and also mister head fouling. I was planning to R/O enough water to supply the misters and continue to water with the untreated shallow well water.

BUT I've read that the calcium and iron cause problems with R/O systems. So I'm wondering if I would do better to run the deep well water in the line to the GH and use R/O water for everything. I'm hesitant to do that because I don't like the water wastage and I'd probably have to buy a larger capacity R/O unit. Also, I need to use the water out of that line to water in the yard. (The GH is 300 feet from the wells.)

Bottom line, is it going to be a problem to use the shallow well water, or will regular back flushing of the unit likely be enough to keep things running well?