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The Right Way to Check and Interpret Pool Chlorine Levels

If your pool has insufficient chlorine levels, it could open you and your family up to a number of infections. Conversely, too much chlorine has negative health effects of its own. Check out this blog post by Best Pro Pool about how important pool service and repair is. Then find yourself a chlorine test kit and get to work!

What's A Pool Test Kit?

Using a test kit for your pool water will take you right back to your high school chemistry class. The kit will come with instructions, which may vary based on the brand, but make sure you pay attention to the specifications. If you're not particularly confident or don't have the steadiest hands, then you should ask pool companies in Merced to help you out.

The reading you'll get will show the level of free chlorine or total chlorine. Some show both, but either will work in this case.

Total Chlorine

During the swimming pool cleaning and chlorination process, chlorine reacts with materials (organic and inorganic) as it's introduced to water. These reactions are necessary for ridding the water of harmful bacteria. The chlorine leftover after this process is complete is called total chlorine.

It comprises "combined chlorine" (chlorine that is no longer reactive) and free chlorine.

Free Chlorine

Free chlorine is the leftover chlorine that's still reactive to bacteria. This is more important to measure.

What Do My Results Mean?

Here's what to make of the following PPM (parts per million):


This is not ideal. If there's 0 chlorine in your pool, there may be live bacteria that could cause illnesses for swimmers.


This is a good level for drinking water but it should be kept higher in a swimming pool. The remaining active chlorine molecules show that bacteria have been deactivated, and any new bacteria introduced will be killed. However, this is on the low side, so keep testing the water to keep the level static.


This is better than the former in that it's on the safer side. However, this is still low, so keep testing the water to ensure stable levels.


This is a better level. Although your pool water will have a slight chemical smell, swimmers will be safe from bacteria and unharmed by the chemicals.

3 Or More

At this point, the level may be starting to get a little high. It would be prudent to ask a pool service to check it out, as you might require further testing.

When it comes to your pool, remember that the smallest slip up could go unnoticed until it causes damage. The monthly pool service packages offered by Best Pro Pool are designed to prevent exactly that, and they're extremely cost-effective as they'll reduce the number of times you need pool equipment repair.

We do residential and commercial pool cleaning in Turlock and many other CA locations. Call us at 209-358-7665 to book an expert today.


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