Anyone who enjoys spending time relaxing in their hot tub with family and friends knows how important it is to keep the water clean. Sanitizers are indispensable in the process, but sanitizers alone are not enough. So how do you achieve perfectly clean, pristine hot tub water? The answer is simple: spa shock. Spa shock or hot tub shock is a super dose of oxidizer that is said to “shock” the water so that it is clean and free of contaminants. If you are ready to learn how to properly shock your hot tub, let’s dive right in.

Why Use Spa Shock?

So, we have determined that we shock a hot tub to clean the water, but why is this different than using your regular dose of sanitizer? Long story short, spa shock performs three important functions.

  1. Kill Bacteria

    • Bacteria in spa water can be dangerous and even cause serious illnesses like Legionnaires’ Disease. It can grow quickly if sanitizer levels have fallen below the recommended range of 1-3 ppm for chlorine or 3-5 ppm for bromine levels. Shocking the spa rapidly raises levels to eliminate dangerous bacteria.

  2. Remove Organic Contaminants

    • Each time a bather takes a dip in your hot tub, oils from their skin, lotions, hair products, and other organic matter end up in the water. This build up can eventually cause cloudy water, so shocking on a regular basis, and especially after heavy use, is important to remove contaminants.

  3. Remove Chloramines or Bromamines

    • Chloramines are the waste products created when chlorine works to remove bacteria and contaminants in your spa, and they are the source of that unpleasant chlorine smell you often find in public pools. Similarly, bromamines are the waste product created by bromine. Although bromamines do not cause an unpleasant odor, they are still unhealthy. Shocking your spa quickly removes chloramines and bromamines from the water.

Types of Hot Tub Shock

There are a few different types of shock that are appropriate for use in a hot tub.

Di-chlor Shock

There are several different kinds of chlorine pool shock, but di-chlor shock is the most appropriate for spas because it is stabilized and can stand up to high temperatures. Chlorine shock is the most common type of shock used in spas. Because of its unmatched sanitizing capabilities, it is recommended for use in any hot tub with a heavy bather load. Use di-chlor shock treatments with chlorine, bromine, salt water, and ionizer or ozonator spa systems.

Non-chlorine Shock

Non-chlorine shock, as the name suggests, does not contain chlorine. Instead, it contains potassium peroxymonosulfate, which is a highly effective oxidizing agent. It is great for removing organic contaminants from the water, and it activates free chlorine or bromine in the water. However, it is not a disinfectant, so it does not kill bacteria in the water like chlorine shock does. Non-chlorine shock can be used with chlorine, bromine, mineral, and salt water systems.

Biguanide Shock

This type of shock, which is actually a special type of hydrogen peroxide, is only used in spas that use biguanide sanitizer.

When to Shock Your Hot Tub

Shock your hot tub at least weekly and more often for heavy use. If it is indoors, any time of day is fine, but if it is outdoors, wait until dusk or dark so that the sun does not burn the chemicals off before they have a chance to work. Wait to resume use until chlorine levels have returned to normal.

How to Shock Your Hot Tub

  1. Before you begin, remove the spa cover and leave it off until you have added all of the hot tub chemicals and given them time to off-gas.
  2. Test the water using test strips to ensure that the pH level is between 7.4 and 7.6. If the pH level is off, be sure to adjust it before shocking the spa water.
  3. Turn the blower off, but keep the circulation pump on so that the water is moving but not too vigorously.
  4. Get your safety gear including goggles and gloves. Shock is harmful to skin and eyes and should be kept out of reach of children and pets at all times. If the spa is indoors, make sure that the room is well ventilated.
  5. Measure your shock into a chemical resistant measuring cup. The amount of shock that you use is based on the size of your spa. Check the shock manufacturer’s directions for this information.
  6. Carefully add shock directly to your spa water, making sure to stand upwind if there is a breeze.
  7. Leave the hot tub cover off for at least 20 minutes after shocking to allow for off-gassing.

By maintaining proper chemical levels including pH, calcium hardness, sanitizer, and alkalinity, and frequently shocking the water, most hot tub owners find that they can keep their spas clean, clear, and free of harmful bacteria. This means more time soaking your tired muscles and less time spent on spa maintenance. If you have questions about any of our spa chemicals, contact our friendly pool experts today at 800-574-7655 or visit us online at doheny.com.