So I've reading and re-reading all the different user manuals I got with my new pool, plus all the info available in this forum. I haven't yet tried to grasp the math that creates correspondence between free chlorine and CYA levels, but I do understand that as CYA levels go up, there is the need for higher chlorine level, too.

My Jandy-made SWCG's user manual gives the following info for "optimal pool water conditions":

Free Chlorine: 1-3ppm (Jandy adds, "Continuous exposure to levels above 3.0 PPM may cause corrosion of pool metals")
Combined Chlorine: None
pH: 7.4 - 7.6
Chlorine Stabilizer (CYA): 50-75 PPM
Total Alkalinity: 80 - 120 PPM
Calcium Hardness: 175 - 400 PPM

Then there's a place, in small print, that adjust the above for water temps above 85 degrees: "...increase the stabilizer to 75-85 PPM, and super chlorinate with other chlorine agents other than the chlorine generator, to reach break-point chlorination."

Questions:

1) Why do SWGC pools generally require higher CYA levels than non-SWCG pools?
2) Why are higher still CYA levels required for warm water (our pool is 89 or 90 degrees right now)
3) If the CYA levels are supposed to be so high, why is the "optimum" level for free chlorine still listed at the low level of 1 - 3 PPM?
4) Is it true that continuous exposure of FC that is above 4 PPM really do cause pool metals corrosion (I have a heat pump, so this point interests me)
5) Do other SWGC shock their pools with liquid chlorine / bleach instead of just using the Boost button on their SWGC?

For the techies and math geeks only: I'm only in my 8th week of pool ownership, but thus far, I've only shocked our pool using the Boost button alone (that runs the SWGC for 24 hours continuously at a 100% rate). Our model of SWGC says that it produces 567gm of chlorine in 24 hours. I've got a 16,755 gallon pool/spa, which is equivalent to about 64,000 liters. So, one 64,000 milliliters is one PPM. If my SWGC generates 567gm in 24 hours, that's nearly 9 PPM of chlorine added to the pool in 24 hours (567,000ml / 64,000ml). My Taylor K2006 kit says my CC level is 0.5 (perhaps less, but no more than), and break-point chlorination is 10 times the CC level, I'm thinking my SWGC creates enough chlorine to superchlorinate my pool once a week without me having to do anything extra.

I only just got my Taylor kit a few days ago, and I use the Boost button starting Sunday morning, so I'll be curious to see if, on Monday morning, my FC level really is 7 or 8 PPM higher than it was on Sunday morning.

Your thoughts?