How should I shock my above-ground pool for the best results?

First, test and adjust pH to 7.2–7.4 and fix alkalinity before shocking — otherwise you’re wasting money. Shock at dusk so sunlight doesn’t burn off chlorine. Follow label dosage, broadcast around edges with pump running (don’t pour into skimmer), and let pump run at least 8 hours. Water will turn cloudy then clear; wait 24 hours before swimming.