What Is Shocking a Hot Tub?

Shocking a spa means applying an ample dose of chlorine (sodium dichlor) or non-chlorine shock (potassium monopersulfate or MPS). One purpose of this treatment is to break-down organic waste contaminants which cause odor and cloudy water. After treatment, water quality and clarity is often completely restored.

When should you shock your hot tub?

The general rule of thumb is to shock your swim spa at least once a week. If it's getting a lot more use than usual or several different people are using it, you may want to consider shocking the water twice a week. Just make sure to test the water beforehand and ensure your pH levels are where they're supposed to be.

How do you shock treat a hot tub?

To shock your hot tub, simply follow these easy instructions.
  1. Adjust the pH levels of your spa's water to between 7.4 and 7.6.
  2. Remove the hot tub cover so your spa can breathe while being shocked.
  3. Turn off the air to the jets but leave the circulation pump running so the water is moving but is not too agitated.
James H. Sterling

James H. Sterling

Environmental Science & Climate Journalist

James Sterling reports on renewable energy developments, climate policy, ecological conservation, and green tech innovations around the globe.