Non-Chlorine Shock: Should You Use It in Your Pool?

Written by Michael Dean
May 22, 2023

non-chlorine pool shock

You likely already know that shocking your pool is essential to keep your swimming pool water safe to swim in, but did you know that you can use non-chlorine shock as a supplement to your regular chlorine shocks?

In this guide, I’ll walk you through the pros and cons of using non-chlorine shock and how to use it.

Main Takeaways

  • The three main reasons to shock a pool are: 1) to get rid of algae, 2) to remove bacteria, and 3) to break up chloramines.
  • Non-chlorine shocks like potassium monopersulfate (MPS) are an excellent alternative to normal chlorine shocks.
  • Non-chlorine pool shocks encourage disinfecting, don’t impact chlorine or calcium levels, can be used on any type of pool, don’t impact CYA concentration, turn water crystal-clear, and can tolerate hot temperatures and UV rays.
  • Unfortunately, non-chlorine shocks don’t kill germs or algae, have high acidity, and can change your total alkalinity levels.

What Is Non-Chlorine Pool Shock?

The process of shocking is critical for your pool’s maintenance because it keeps your swimming water clear and safe.

There are three main reasons why you need to shock a pool. They include:

  • Getting rid of algae
  • Removing bacteria
  • Breaking up chloramines

Usually, people use chlorine to shock their pool because of its effectiveness in addressing these three pool issues. Nevertheless, it isn’t the only option for keeping your pool oxidized—non-chlorine shocks like potassium monopersulfate (MPS) are an excellent alternative.

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Like chlorinated shock, MPS comes in powder form. There are many advantages to using MPS over chlorine, and I’ll share them with you next.

Benefits of Non-Chlorine Pool Shock

Because of all the variables that affect pool water, there’s no set number regarding how often you should shock your pool. However, chlorinated shock has its disadvantages because sunlight breaks it down. Furthermore, the more chlorine works to clean your pool, the less effective it becomes.

That’s where non-chlorine comes into play as an excellent supplement to your routine chlorine pool shocks. Ready to learn about all the benefits of shocking your pool with non-chlorine? Let’s begin!

Encourages Disinfecting

Non-chlorine shock excels at cleaning pools because of its oxidizing properties. It oxidizes water by eliminating oil and organic materials in your pool.

That said, non-chlorine shock functions best when paired with chlorine shock. That’s because chlorine loses its strength the more it has to work. Therefore, by non-chlorine shock taking care of oil and organic matter, the free chlorine that’s already in your water can spend its time disinfecting your pool—a feature that non-chlorine shock doesn’t have.

Long story short, non-chlorine will oxidize your pool, keeping it clean of oil, hair, and other organic matter from nature and the human body. That way, chlorine can put its strength into sanitizing your pool, ridding it of bacteria and health-threatening water diseases.

Doesn’t Impact Chlorine Content

Non-chlorine shock is just what it sounds like—you won’t find chlorine on its ingredient list. Furthermore, if you supplement your pool care with bromine, you won’t have to worry about non-chlorine impacting the water’s bromine levels.

The reason that it’s so crucial for non-chlorine shock not to alter the chlorine content if it had chlorine in it, is that chlorine could mix with the chlorine already in your pool, creating chloramines.

According to the Centers for Disease Control and Prevention, chloramines are dangerous because they attach to body waste from swimmers. At best, you might feel a little eye or skin irritation. At worst, it could affect your respiratory tract. The chloramines can even turn into gas, harming the air around indoor pools.

Well-Rounded Substance

When you use chlorine to shock water, you must be careful because it’s a harsh treatment that can discolor or damage vinyl pool liners. However, you can use non-chlorine shock on any type of pool or water situation, including:

  • Inground
  • Semi inground
  • Above ground
  • Saltwater system

For this reason, pool owners looking for gentle treatment for their water prefer using non-chlorine shock to supplement their chlorine treatments.

Doesn’t Impact Cyanuric Acid Concentration

If you haven’t heard of cyanuric acid, you’ve likely heard of this—pool stabilizer. You need to use cyanuric acid as a pool stabilizer to protect the chlorine in your pool from the sun.

UV rays can destroy chlorine in as little as a few hours if your water doesn’t have a pool stabilizer. Nevertheless, too much cyanuric acid is bad for your pool water; it’ll reduce the chlorine’s sanitizing effects.

Therefore, you can rest easy using non-chlorine shock because it won’t disturb cyanuric acid concentration.

Leaves Calcium Levels Alone

By now, you’ve probably gathered that non-chlorine shock is a gentle treatment that doesn’t interfere with many other necessary chemical and compound balances in your pool. The same is true for calcium levels.

Calcium in water is normal, especially since most chlorine shocks contain calcium hypochlorite. The issues arise with too much calcium in your water since it causes scale.

Scale is a nasty white or grey build-up on siding, filters, and other vital equipment and mechanisms for your pool. It can be challenging to remove, and in some cases, the damage may be permanent.

However, using non-chlorine shock in your pool gives you peace of mind since you won’t have to worry about increasing the calcium levels in your water.

Returns Water to a Clear State

No one wants to swim in cloudy water, and shocking your pool will prevent the algae and bacteria that cause this. However, I recommend having a maximum chlorine level of four parts per million.

Therefore, if you’re on the cusp of going over this recommendation, adding non-chlorine shock is an excellent way to get crystal-clear water back into your pool without risking the adverse health effects of too much chlorine.

Tolerates Hot Temperatures

Not only does non-chlorine shock work well under the sun, but it also functions well under extreme heat.

Hot tubs and spa water can often reach temperatures of over 100°F. However, these high temperatures alone aren’t enough to kill bacteria and organic matter. That’s why it’s beneficial to use non-chlorine stock—it’ll oxidize hot water just as well as it oxidizes lukewarm pool water.

Timing Doesn’t Matter

If you have experience shocking your pool with chlorine, you know you’re not supposed to do it in the sun because the UV rays will destroy the chlorine’s properties. Furthermore, you must wait for at least one hour per pound of chlorine shock before swimming in your pool.

On the other hand, non-chlorine shock isn’t sensitive to UV rays, so you can use it in your pool at any time during the day. You can also jump back in the water a mere 15 minutes after you shocked the water.

Drawbacks of Non-Chlorine Pool Shock

Although non-chlorine has more favorable properties than bad ones, there are a few drawbacks you should keep in mind before shocking your pool with it.

Doesn’t Kill Germs

Non-chlorine is an oxidizer, meaning it does a great job cleaning up oils and organic matter. However, it doesn’t actually kill bacteria or algae—you need chlorine for that.

Therefore, you always need to use non-chlorinated shock with chlorine to keep your pool water healthy for swimming.

High Acidity

Non-chlorine shock, such as MPS, has an average pH level of 2.3. Let me put that into perspective: the ideal swimming water should have a pH level between 7 and 7.6.

Therefore, if you shock your pool with too much MPS, you’ll have to treat the water to get the pH levels back to a healthy range. On the other hand, you don’t have to worry about chlorine shock impacting the pH levels long-term because the sun will fix any pH imbalances.

Change to Total Alkalinity

Total alkalinity determines how well water can neutralize acids. When applied in significant quantities, non-chlorine shock can cause your pool water to have unhealthy total alkalinity levels.

Furthermore, the total dissolved solids content will simultaneously increase. Therefore, measuring your pool’s total alkalinity and total dissolved solids levels after applying non-chlorine shock is essential to ensure they’re in balance before you jump back in the water.

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How to Use Non-Chlorine Pool Shock

With so many advantages that non-chlorine shock offers, you’re likely wondering how to use it. Here’s some good news: It’s quick and easy!

I’ll walk you through the steps here to get back to enjoying your pool.

  1. Protect your skin. If non-chlorine shock touches your body, it won’t have as many of the painful side effects that chlorine shock does. Nevertheless, you should wear goggles, gloves, a long-sleeve shirt, and pants.
  2. Figure out the measurements. Typically, you’ll need to use one pound of non-chlorine shock for every 10,000 gallons of pool water. You can use my calculator to determine the amount of pool shock you need.
  3. Prepare the solution. Although you can technically pour the non-chlorine shock directly into your pool, it’s best to scoop up some of your pool water in a bucket and mix in the powder shock first.
  4. Apply the solution to your pool. Circle the perimeter of your pool and pour the non-chlorine shock into the water. Focus on the areas with jets, as they’ll help circulate the solution through the water faster.

If you’re unsure about the ratio of shock you put in your water, run a test after 15 minutes to ensure the pH, total alkalinity, and total dissolved solids content are where you want them to be.

After 15 minutes, your pool is safe to use and enjoy.

That’s about it for non-chlorine shock. Have questions? Drop me a line.

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