I just finished reading through the Pool School and I had a question about one statement. On the Definitions and Abbreviations page under dichlor and trichlor is the following line:
"Causes CYA to rise with continued use so it is not a good choice for those with cartridge filters or in climates [...]"
Why are cartridge filters explicitly called out there? I couldn't find any other such reference to explain that in the entire school. I have a cartridge filter, so I'm curious about what makes it unique in relation to CYA.