How often should I shock my Spa? Ciara June 18, 2018 01:37 Updated Follow You need to use an approved oxidizer (spa shock) at least once a week or after heavy usage of your spa, spa shock oxidizes the organic matter that makes the water cloudy.Important: If you are using a chlorine free sanitizing system you will need to shock the water with a Chlorine Free Shock (Poppits Quick Fix) go through guidelines on the brand. Related articles Can I use spa shock with my purezone filter? When should I change my Spa Water? Why does my spa water get cloudy? Comments 0 comments Article is closed for comments.