Skip to Content

How Often Should You Shock a Pool?

Shocking your swimming pool will prevent algae and spike your pool’s chlorine levels. Pool shock also works with some algaecides as a super deterrent against algae.

However, too much shock can cause chemical imbalances and other unwanted problems. That’s why it’s important to know how often you should shock your pool.

You should shock a pool once per week during the warmer months and once every other week during the colder months. Shock the swimming pool when the chlorine drops between 1ppm to 2ppm, but don’t add any shock if the chlorine is around 4ppm to 5ppm. Use a high concentration of calcium hypochlorite.

In this article, I’ll cover whether or not you need to shock your pool weekly, what happens if you shock it too much, and whether or not you can shock the water two or more days in a row. Let’s get started!

Do You Really Need to Shock Your Pool Every Week?

You need to shock your pool every week when it’s hot outside, especially if your chlorine levels get too low.

I suggest never letting your chlorine dip below 2ppm because it won’t prevent algae blooms, bacteria growth, and cloudiness. Shocking the pool will spike the chlorine up to 5ppm to 6ppm.

Shock is one of the many chemicals needed for swimming pools. However, it shouldn’t be overdone. While it’s quite necessary, it’s also very easy to overload your pool with too much chlorine.

The water will be unbearable to swim in, not to mention the fact that chlorine can affect the pool’s appearance.

You should shock the pool once every week when it’s hot outside because the sun’s evaporation can reduce the chlorine levels. Furthermore, the ambient warmth increases algae blooms, using most of the chlorine in the water.

Excessively high chlorine levels can make the pump scream and screech because it burns through the motor. Adequate chlorine circulation is great for the water, but too much of it can corrode the pool equipment.

Below, I’ll show a few more examples of what happens if you shock the pool too often.

Can You Shock a Pool Too Much?

You can shock a pool too much if you add it when your chlorine is always above 6ppm. High chlorine levels will cause skin and eye irritation, damage the pool liner, and harm the equipment. Too much chlorine can be hazardous, creating a swimming pool that you and your pets shouldn’t get in.

Does it always seem like your pool pump is leaking? If so, it might be because the chemicals are imbalanced. High chlorine levels, low pH, and excessive hardness can ruin the pump’s bearings and impeller.

Here’s a list of signs that you’re shocking the pool too often:

  • The chlorine is always above 6ppm. Your chlorine levels should hover between 2ppm to 5ppm.
  • The water looks clouder a day or two after shocking the pool. Cloudy water is often a sign of dead algae, but if there’s no algae in the water, it likely means you’re using too much chlorine.
  • There’s a big differential between the total chlorine and free available chlorine. The free available chlorine is the active, useful chlorine. The total chlorine is the FA chlorine combined with ‘dead’ and useless chlorine. Too much total chlorine saturates the water and makes it look cloudy.
  • Your pool equipment and liner are deteriorating. Frequent shock treatments can permanently damage the gunite, fiberglass, or vinyl in your swimming pool. It’s highly corrosive in strong concentrations.

Shocking your pool is a double-edged sword that needs to be controlled. It’s one of the most effective pool treatments, but it can quickly be overdone.

If you don’t know when to shock your pool, read on.

How Do You Know When to Shock Your Pool?

You should shock your pool when there’s algae, the chlorine levels are below 2ppm, and when the water looks cloudy. While most schedules suggest weekly shock treatments, it’s better to base the shocking schedule on your chlorine levels.

Here’s a list of circumstances that you should shock the pool:

  • Shock your pool after it rains. The rain can bring a lot of phosphates into the water, which is one of the algae’s primary food sources. Shocking the pool before the algae forms will prevent it from becoming a problem.
  • Shock your pool after a day of lots of swimming. People and pets bring a lot of sweat, bacteria, hair, and other debris into the pool. All of these things are perfect for algae growth.
  • Shock your pool before winterizing it. Winterizing includes shocking, adding algaecide, and balancing the pH and alkalinity. It prevents the water from getting dirty during the colder months.

Can You Shock Your Pool Two Days in a Row?

You can shock your pool two days in a row if you’re using a compatible algaecide treatment or if there’s a lot of algae in the pool.

Never shock the pool multiple days in a row if the chlorine is too high or if the water looks white and murky. Excessive amounts of chlorine can cloud the water, making you think there’s algae.

While you can shock your pool too much, you might need to do it a couple of times to take effect.

You can shock your pool a couple of days in a row if the chlorine levels aren’t high enough. The shock treatment usually takes a few hours to work. If you test the water and it’s still below 2ppm, you could shock it again the next day.

However, keep these three things in mind if you want to shock your pool two days in a row:

  1. Make sure the chloramines aren’t too high (they’re the leftover, unusable chlorine from the previously mentioned total chlorine example).
  2. You can shock the pool two days in a row when using Coral Seas Green to Clean. Green to Clean is hands-down the best algae treatment I’ve ever used in a swimming pool. Combine two pounds of Green to Clean with two pounds of shock, then do the same treatment the following day to get rid of the worst algae blooms.
Coral Seas Green to Clean Algae Treatment (4 lb.)

Pro-tip: Don’t shock the pool if you expect people or pets to get into the water within the next six hours. The water won’t be swimmable until six hours after you shock it.


  • Jonah Ryan

    Jonah has worked for several years in the swimming pool industry installing and repairing equipment, treating pools with chemicals, and fixing damaged liners. He also has plumbing and electrical experience with air conditioning, ceiling fans, boilers, and more. When he's not writing for Temperature Master, he's usually writing for his own websites, and

As an Amazon Associate, we earn from qualifying purchases. We may also earn commissions if you purchase products from other retailers after clicking on a link from our site.