Shock Chlorine: Why, When And How To Use It?

Shock chlorine is commonly used among pool owners. Before we go into why, when, and how to use it, let’s first go over what shocking is. Shocking is the process of adding chemicals (most commonly chlorine), to your pool in order to quickly raise chlorine levels or to kill dangerous bacteria and algae build-up.

Why To Shock?

Here are the main reasons to use pool shock:

1. To raise the chlorine level quickly. Sometimes your chlorine level will get very low very quickly, especially in pools that see a lot of use. Since chlorine is necessary to kill harmful bacteria and make the pool safe to use, we need to quickly get the levels back to normal before bacteria, algae, and other harmful pathogens invade the pool.
2. Algae growth and/or green water. When your water and pool turn green, this means you have algae and bacteria living in your pool and you definitely need a shock treatment ASAP. This can happen for many reasons. Some of the most common reasons for algae in a pool are recent rain, thunderstorms, and extended periods of sun.
3. High levels of chloramines. Have you ever been near a hotel or gym pool and noticed the highly strong smell of chlorine? That strong smell is not a good sign. It is a sign of imbalanced water levels. The smell comes from chloramines that give a pool that strong smell and can also be very irritating to our skin and eyes.
4. When opening and closing your pool. When opening your pool, you should shock your pool to kill germs, and clarify the water. When it's time to close your pool, shocking will help fight off contaminants over the long winter months.

When To Apply Shock Chlorine?

A common rule of thumb is to shock your pool about once a week to properly maintain your water chemistry. This is also dependent on the use of the pool, the weather, or other environmental factors. But, always be sure to test your pool levels before shocking it.

How To Shock A Pool?

Ideally, you should always use pool shock in the evening after the sun goes down. This is because the sun will burn off some of the chlorine, which will make it less effective. You should also always wait a few hours before taking a dip. Indeed, the high levels of chlorine will be very irritating to the skin and eyes.

Still Have Questions?

If chlorine still confuses you, you might want to read one of our other blog article. We also provide a wide range of pool-related articles in our blog!