Pool Shock Essentials: When, Why and How to Shock Your Pool

Jun 11th 2024

As a pool owner, you understand the importance of maintaining crystal clear water. However, there are times when the usual maintenance routine isn’t quite enough. Your pool water may need a little extra help to keep it clear and bacteria free. That's when you need to know how to shock a pool.

What is Pool Shock?

Pool shock is a chemical treatment used to sanitize swimming pools and hot tubs. Pool shock treatment is highly concentrated with chlorine, which is great for killing bacteria and other impurities in the water. You can use pool shock regularly or when you notice specific water quality issues.

Why Do I Need to Shock My Pool?

There are a few reasons why shocking your pool is important. When lots of people swim in your pool, the chlorine levels can drop, leading to bacteria and algae growth. Also, heavy rain or windy days can introduce environmental contaminants into your pool. Even sunscreen can throw off your water balance, causing an unpleasant smell and cloudy water. These are all good reasons for pool shocking.

When to Shock a Pool

During swim season, it's a good idea to shock your pool water at least once a week – more often after a party or bad weather, notes Homes & Gardens. Signs like algae, foamy water or cloudiness mean it's time to shock your pool.

Interestingly, you shouldn’t normally smell the chlorine in your pool. If you do, says Swim University, that means the chlorine is no longer sanitizing the water and it’s time for a shock treatment.

Before you shock your pool, test the pH and chlorine levels. Your local pool expert can help you understand the optimal chemical levels for your pool.

Choosing the Right Pool Shock

Pool shock comes in liquid, powdered, or granular form. They all work the same way, but there are differences in the way they are used.

Liquid shock for pools is typically more budget-friendly. It tends to sanitize more quickly and can be added directly to the pool water. However, splashes and spills can be dangerous and must be handled carefully. Liquid pool shock is corrosive and harmful to your skin, eyes and respiratory system.

Pool shock powder can be stored for longer periods and is easier to carry. Most granular pool shock must be dissolved in a bucket of pool water before adding the treatment to the pool. It may create residue that should be vacuumed before going back into the pool.

man's torso from chest to thighs, wearing blue uniform and holding a bucket of chlorine, pool testing kit and cleaning equipment

How to Shock a Pool

Before you add pool shock, make sure the pH level of the pool water is between 7.2 and 7.8. You may need to adjust the pH using a pH increaser or decreaser. Then, add the right amount of shock based on your pool's size and chlorine levels.

How much shock you need is determined by the size of your pool and the type of shock you use. When using calcium hypochlorite or sodium dichlor, two granular shock treatments, you typically use one pound of shock granules for every 10,000 gallons of water. For sodium hypochlorite, or liquid chlorine, use 10 ounces for every 10,000 gallons of pool water.

Pool Calculator offers this formula: Length of your pool (feet) x width (feet) x depth (feet) x 7.5 = volume in gallons.

Keep in mind that when treating algae, you may need to double or even triple the amount of pool shock.

When handling pool shock, always wear gloves and eye protection and follow the manufacturer’s instructions carefully.

Keep your pool pump running while adding pool shocking chemicals and for six to eight hours afterward. Test the chlorine level afterward and add more shock if needed.

What Does Pool Shock Do?

Shock provides a mega-dose of chlorine to your pool in order to quickly raise the chlorine level. The combination of shock and chlorine tablets sanitizes pool water and keeps the chlorine level high enough to continue to kill harmful microorganisms.

A pool shock treatment also will likely raise the water’s pH level and may make the water cloudy for a while.

Getting Back in the Pool

You should wait at least 24 hours after shocking your pool before using your pool, notes Health. Test the water and make sure chlorine, pH and other chemicals are at safe levels before letting anyone back in the water.

Shocking your pool water is a quick and easy way to keep your pool sparkling clean. Just remember to always wear gloves and eye protection when handling the shock treatment and follow the manufacturer's instructions.

Give your pool a little extra TLC! With regular shock, you can enjoy crystal clear water all season long.

Shop Christmas Central's Pool & Spa Store for pool chemicals, pool floats and equipment.

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