Pool shock works by rapidly raising chlorine levels to oxidize organic contaminants like sweat, sunscreen, and algae. It breaks down chloramines (combined chlorine) and restores free chlorine sanitization power.
You typically don't need to shock if free chlorine is genuinely high, but you should test for combined chlorine (chloramines) first. High total chlorine with low free chlorine indicates you need to shock to break down chloramines.
Yes, pool chlorine can make you itchy, but it's usually not the free chlorine itself causing the problem. Combined chlorine (chloramines) and improper water chemistry are the main culprits that create skin irritation.
