Pool Chlorine

[hockeyrick]

Sanitizer is anything and any method you use to kill bacteria.
Once stabilized, calcium, alkalinity, and cyanuric acid level just need to be checked every 3 months. They usually don't change much unless your water does-that is, you backwash out a lot, lots of rain water and you drain off.
keep in mind evaporation leaves chems in your pool, its only when you pump out water does it change the percentage.

Source water is not a big deal here in Thailand, usually it is low on calcium, as opposed to calif. which is usually high. 200-450 ppm is a good range. For me, less is worse than more, but you see the after affects over a few years, so its a slow process. Same for ph, low ph is worse than high, just as a rule of thumb.
But all 5 should be tested, but here nobody does except me and Platinum Pools, and most owners usually are too cheap to add the chems. Sorry, but just what I have seen from my interactions with foreign owners.

[Nereus]

Source water is not a big deal here in Thailand, usually it is low on calcium, as opposed to calif. which is usually high.

Sorry, but you are completely wrong about this. I do not have the exact figures, but I can assure you that the underground water in many places in Thailand will block up a salt water cell in less than a week. Just as it will block up certain types of water heaters, not to mention nothing of the rapid accumulation of calcium deposits on plumbing fittings such as taps. (faucets).

[hockeyrick]

As a rule, the calcium levels are on the soft side, of course there are exceptions!!!!!!
That just means you manually clean the cell or it does it automatically!

Excuuuuuse me for making a blanket statement!