Hey Pool Owners! Which type of shock should you use in your pool: chlorine shock or non-chlorine shock? Chlorine shock is a powerful, super-concentrated dose of chlorine that helps kill algae growth and bacteria. But it’s a harsh chemical and you’ll have to wait at least 8 hours before swimming again. Non-chlorine shock is great to help refresh your sanitizer, but it won’t battle bigger issues like algae. So for regular maintenance, use non-chlorine shock. And for serious issues and problematic