CYA degrades more rapidly at high water temperatures. It is more of a problem in AZ & TX then NJ.
Degradation of Cyanuric Acid (CYA)
Yeah--I think mknauss has reported somewhere how much CYA he loses in sunny Laughlin, NV. It's not completely insignificant, as I recall. The first two seasons that I opened my pool here in Idaho, I had the opposite problem. Winter consumed ALL my CYA. This season was different--maybe because the winter wasn't as long or as harsh or maybe because my pool chlorine chemistry is still borked from the sulfamic acid/Jack's #2 treatment I did late last season.
I use whatever I need for the desired chemistry. LC is the most expensive form of Cl for me right now. Trichlor is the cheapest source of both Cl and CYA (It's like buying stabilizer super cheap and getting the Cl for free.) In 50 lb online purchases, trichlor pucks might even be cheaper than SWG electricity and cell replacement reserves. For SLAMming this year, I used two mesh bags with 10lbs each of trichlor pucks (positioned right in front of the return jets) hung from 1x2 lumber on paracord. SLAM Cl levels were achieved literally overnight (CYA was initially 30 and I needed higher in preparation for new SWG).
When I first got this house and pool, I started a SLAM with trichlor pucks after pulverizing and dissolving them in 5 gal. buckets of water. It's a lot of work with nasty stuff though. (Don't breath the dust!) Hanging mesh bags in front of jets is much easier and safer, if CYA is low enough to warrant the use of trichlor at all.
Once my CYA is where I want it, I'll use cal-hypo for a SLAM, assuming I can handle the CH increase, which is usually embraced due to CH splash-out and filter backwashing losses. LC has increased in price so much in this panic-demic year that even cal-hypo is a cheaper Cl source than LC but, after I got my CYA and CH where I wanted them, I pushed the button and powered-on my new SWG only about two weeks ago.
