salt water pool in AZ

Ben,
When you say "calcium carbonate" is that the snowflake looking stuff?

Calcium carbonate is just limestone or marble dust (used in plaster) -- it's not something you add to your pool. Rather it forms when you have excess carbonate ions (from sodium carbonate or bicarbonate), calcium ions (from calcium chloride flake or beads, calcium hypochlorite . . . or your pool's walls), all at a high-ish pH level.

Probably, you are thinking of calcium chloride. The dihydrate (77% calcium chloride) is a flake; the anhydrous (90+%) is usually beads. The dihydrate (chemically bound water) is far more commonly sold than the anhydrous (no water) material).

Was AFK for a couple of weeks. Neat to see the additional info. It's rubber meets the road time, as we are submitting for permits. I have to make a decision on what mfg of equipment we're going to specify. With the info I've seen in the forum, I feel more confident. Thank you.

Good luck with your project--let us know how it's going!!

Quick question - was just looking at Doc's review of SWCG on another post...what is the salt range and how important is it? I notice two manufacturers have a very wide range, while the majority have a much tighter range.

I'm not 100% sure of the answer, but I would say that the range is dependent on the unit. Each unit will specify the salt range necessary for it to work correctly. If the salt level is too low, then it won't produce the chlorine you need.
There are SWCG'ers around here that I'm sure will chime in and give you a more definitive answer, though....

Each SWCG has its own requirements. Aylad is spot on right. You have to satisfy YOUR unit in order for it to produce adequate amounts of chlorine. 5 different pool stores (or tests) will give you 5 different salt levels. In the end, your Low Salt light or Salt Level Indicator on your unit must be satisfied for the unit to work correctly. And BTW cold water will affect your units ability to detect proper salt levels, so you can expect to see "Low Salt" warnings in colder weather, and consequentially, below about 60° F, your unit probably won't produce chlorine anyway.