Chlorine tablets can feel like the simplest path to a clean pool, until the water starts fighting back. We dig into what really happens when trichlor becomes the main sanitizer: cyanuric acid (CYA) climbs, chlorine gets “slower,” and algae can show up even when your test kit says the free chlorine looks fine. We walk through the practical chemistry behind it, including why CYA is more than just “sun protection” and how a rising stabilizer level changes what a safe chlorine target should be. ...