I have a SWG pool, and have been educating myself about CYA / chlorine ratios. I had not understood the relationship between CYA and chlorine, and have run my pool for the last few years with free chlorine levels of 1-3 ppm, and CYA levels of 20 -50 ppm. The pool water has been fine, with one or two episodes of cloudiness that tested very low chlorine, and responded to winding up the chlorine output for a few days (I have never shocked my pool). I am fascinated & puzzled by the recommendations and posts on this forum for high CYA levels in SWG pools compared to non-SWG pools, as my experience with low CYA levels has been good, with little sign of algal growth.
The CYA / chlorine chart has tables for non-SWG and SWG pools: these are very useful guides, but the obvious question is why is the range of CYA for SWG pools restricted to 60-80 ppm: are these tables saying don't run your SWG pool with a CYA less than 60, or is it OK to use the non-SWG table for lower CYA levels? What extra benefit does high CYA offer (over lower CYA) in a SWG pool? I have seen the posts about less chlorine consumption at high CYA, and appreciate that the free chlorine level is a lower % in the SWG table compared to the non-SWG table.
Apologies for all the questions, but I am perplexed, and trying to figure this all out.
5000gal pool, Zodiac chlorinator, Rolachem acid peristaltic pump, Waterco zeolite filter (in southern part of Australia)