How to SLAM a Pool in 6 Steps

How to SLAM a Pool

The term SLAM is quite common among pool owners. Experienced ones know what it means, its importance, and how to do it for their pools, but it often sounds a bit foreign for new pool owners.

SLAMing your swimming pool is a crucial part of keeping it clean and sanitized, but you can only do it well if you know what it is all about. A good starting point is to understand what the term means.

What Does SLAM Mean?

SLAM is an abbreviation for Shock, Level, And, Maintain. The word outlines the steps and processes involved in SLAMing your swimming pool.

With SLAM, you have to shock your swimming pool using a higher chlorine concentration than you would use for a regular pool shock. The main aim is to eliminate bacteria, algae, viruses, and other organic compounds in the pool water.

From the onset, it is essential to note that the massive doses of chlorine you need when SLAMing your pool pose serious health risks like causing respiratory system problems. Therefore, before you decide to SLAM, you have to make sure you can do it safely with the keenness required.

Nonetheless, shocking your swimming pool is still one of the best ways to restore your water to a good condition when regular pool shock does not seem to work. It comes in handy when dealing with massive levels of combined chlorine and problematic algae blooms that keep coming back.

Another good thing about pool SLAM is that you can do it on almost any pool because when done correctly, it will not bleach or damage delicate pool materials.

How to SLAM a Pool

SLAMing your pool is not a hard job as all you need is to gather the necessary supplies and prepare your pool by skimming to remove debris and making sure your filtration system is working correctly.

Here is a more comprehensive breakdown of how to do it, starting with everything you will need.

What You Need


Step 1: Test and Adjust Pool pH

While it is crucial to keep track of your pool pH and maintain it at the optimal level, it will be even more important to do it when you plan to SLAM your pool.

Adding the high dose of chlorine to your pool will give you unreliable pH readings, and so you to keep it at the lower end of the required range, which is around 7.2.

A pool pH of between 7.2 and 8.0 is often safe enough for the swimmers. However, the CDC recommends the maximum level should be 7.8.

You can use a pH reducer like the Clorox Pool&Spa 12105CLX pH Down to bring the pH down to the level you want, but if it is below 7.2, you can quickly raise it with baking soda.

Step 2: Check CYA Levels

Next, you need to check your pool stabilizer levels. Remember that a pool stabilizer (cyanuric acid) will affect the performance of chlorine significantly. A pool stabilizer minimizes the breakdown of chlorine, allowing it to remain in the water for longer, which is crucial for SLAM.

A swimming pool should have a cyanuric acid level of between 20 and 50 ppm for your free chlorine to remain effective at sanitizing your pool water long enough. The same level is also optimal when you want to SLAM the pool, and so you should test and balance it.

It is still possible to SLAM the pool with no issue if the level is a little higher than this, but if it is over 90 ppm, you must bring it down by diluting your water before moving to the next step.

Read More: How to Lower High Cyanuric Acid in Pool

Step 3: Add the Chlorine

Once you get the pH and pool stabilizer to the required levels, the next step and perhaps the most important one when SLAMing your pool is to pour in the chlorine.

The most crucial thing is determining the exact amount of chlorine to add for the desired results. Typically, the amount of chlorine you need will depend on the specific level of pool stabilizer you have in your pool.

If you have a pool stabilizer at 50 ppm, you will need around 20 ppm of free chlorine. You can use these numbers to calculate the specific amount you need based on your CYA level.

Technically, it is still possible to SLAM your pool when your pool stabilizer level is higher than 50 ppm. But then, this means you will need to use more chlorine, making the job more expensive for you. Therefore, you are better off getting CYA level to the optimal level before you add chlorine.

Make sure you add the chlorine in the path of your return jets, as this will ensure it circulates faster in the pool to speed up the job.

Step 4: Maintain the Chlorine Level

You need to maintain the free chlorine level from the step above to ensure SLAM will be effective for you. The only way to do this is by constantly testing your free chlorine levels and adding more.

While some pool owners prefer to test the chlorine level every hour, doing it after 2 or 3 hours works fine. The frequent testing at the beginning is necessary because bacteria and other organic contaminants in the water will use up the chlorine fast.

However, as more of the contaminants die, the pool uses up less chlorine. Therefore, the free chlorine levels will start remaining stable for extended periods without adding more, so you can reduce the testing frequency. Once or twice every day should now be enough.

Step 5: Clean Your Pool Thoroughly

If you want to use your pool within a shorter time when SLAMing, you have to clean it well. Skimming, vacuuming and brushing your pool to remove floating debris and the dirt at the bottom of the pool or the walls speeds up the job.

Step 6: Be Patient and Check for Signs SLAM Worked

You have to be patient when you decide to SLAM your pool, as it is not a quick fix. SLAM can take anywhere from a few days to a week, and so you should do it when you are ready to go several days without using your pool.

There are a few signs you can use to know your SLAM worked and your pool is ready for use. They include an absence of cloudiness in the pool, water maintaining free chlorine level overnight an amount combined chlorine level in the pool being less than 0.5 ppm.

Lastly, remember to check the pool chemistry one more time before using it to ensure SLAM does not throw anything off balance.


When dealing with bacteria or algae blooms that will not go away and your regular pool shock treatment does not seem to work, it is time to SLAM your pool.

SLAMing entails adding a higher dose of chlorine to your pool than a pool shock delivers and maintaining it over a more extended period to ensure it does not miss any contaminant.

If you SLAM your pool correctly, by first testing and balancing pH and CYA levels and adding enough chlorine, you can take care of any problematic contaminant.

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