Maintaining Your Pool’s Chlorine Levels in the Summer

landscaping around a poolWith summer arriving on June 21st, the temperatures are already rising rapidly here in North Texas. Thank goodness your pool is clean and sparkling, waiting for you to hop in and cool off! –Or is it?

Are you aware that, with springtime rain, hotter temperatures, and increased sunlight exposure, you may need to use significantly more chlorine in your pool than the Spring and Autumn seasons? Heat, sunlight, runoff, and increased pool use all factor in significantly when it comes to sustaining appropriate chlorine levels.

Sun Valley Pool Service is here to assist with your pool care needs. Click here for a free online estimate!

Let’s explore some significant factors in keeping your pool balanced and user-friendly:

Checking in After Heavy Spring Rain

If you’re a pool owner, you likely already have a springtime pool-ready regimen in place. But let’s take a moment to make sure your routine is fine-tuned. Have you checked the filter system to make sure it’s fresh and running well? Is your pH sitting between 7.2 and 7.6?

If things are looking a bit out of balance, then it’s time to talk a moment about all that Spring rain that blessed your back yard with lush greenery. How is your pool doing- a bit full with leftover rainwater? Have you considered the after-effects of everything that rain brought with it into your pool water?

This can make a significant difference in the overall health of your pool and pool system. Chlorinated water gets diluted by rain, so it’s critical to restore all your chemicals are restored to a level that’s safe for swimmers.

The dirt and bacteria washed in by those rainstorms puts an extra strain on your chlorine levels, because they’ve been busy attacking unwanted microbes to keep your water clean. But that’s not the only thing that’s making your pool’s chlorine work extra hard as Spring turns to Summer!


Unless you’ve got a well shaded pool, your chlorine levels are unfortunately just as vulnerable to UV rays as the precious skin you carefully screen in the summer sun. It may sound unbelievable, but your chlorine levels can drop by up to 90% in only a couple of hours during nonstop sun exposure.

This is caused by UV rays’ ability to break down chlorine on a molecular level, causing it to get released into the atmosphere as a gas. You may have begun the day with perfectly sound chemical levels in your pool water, but who knew it could go downhill so quickly in the sunlight!

Free chlorine is a term used to reference the amount of chlorine in your water that isn’t already hard at work breaking down unwanted microbes. This means that a portion of the total chlorine is always already at work, munching away at algae, bacteria, and other organic materials.

common pool problemsIn addition to the fact that UV rays cause chlorine to break down, the sunlight also encourages algae growth in your water. That means, on a sunny day, the chlorine in your pool is on double duty!

For safe swimming conditions, you need to keep your free chlorine levels at 1 part per million. This means that, on a sunny day with lots of swimming, you want to continue monitoring your pool’s chlorine and adding more when necessary.


As if the sun’s rays weren’t already taking enough of a toll on your chlorine levels, the accompanying heat is doing its own damage. On a hot summer day, every 10* over 80*F can double the amount of chlorine you need in your pool.

This is because bacteria loves warm, wet environments. We thought this critical chemical was on double duty, but turns out it’s triple! And yet, there is one more complicating factor brought on by hot weather.

We all know that water evaporates in extreme heat. You may also be losing some chlorine as well, but the evaporated water isn’t taking all that nasty bacteria along with it. In the Texas heat, your pool (depending on its size and shade coverage) can lose up to an inch per day of water.

That means your free chlorine levels are left battling a slightly denser ratio of water versus bacteria. Did we say triple duty? Let’s make it quadruple!

Pool Use

Most importantly, let’s not forget the very reason you’ve got a pool- to¬†get in that cooling water and enjoy it. Sadly, the oils and other organic materials we bring along just give the chlorine yet another job to tackle.

The hotter and sunnier it is, the more chlorine you use. And yet, the hotter and sunnier it is, the more you want to enjoy your pool! As well you should. But just as it takes care of you by offering a sweet refreshing oasis in the heat of summer, you’ve got to take equally good care of your pool water.

As we mentioned before, it’s important to keep your free chlorine levels at a healthy working ratio to continue combating detrimental particles in your pool water. When you and your family jump in, that ups the ante even further. All the more reason to diligently check and maintain healthy chlorine levels to keep everything- and everyone- clean and safe.


  • Runoff from Spring rains can leave your pool water contaminated with extra dirt and bacterial. Check your filter system and your pH levels to be sure you’re starting off the summer season with fresh, clean water.
  • Sunlight does a number on chlorine levels in more ways than one. Be sure you’re accounting for evaporated chemicals and keeping your free chlorine at a safe level.
  • Heat can cause evaporation, while propagating bacterial growth. This adds extra work for your pool’s chlorine, causing it to deplete much faster than it would in cooler weather.
  • Regular pool use takes an additional toll on chlorine levels, due to the surplus of organic materials we bring into the water.

test pool chemicalsA well-maintained pool can handle a lot of traffic in the glorious heat of the summer sun. Just make sure you’re mindful of your pool’s chemical levels, so they stay balanced.

A healthy pool has adequate chlorine to keep harmful microbes at bay without harming swimmers. For more advice on problem-solving your pool care issues, check out this helpful article!

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One thought on “Maintaining Your Pool’s Chlorine Levels in the Summer

  1. My dad would like to hire a service that will be able to maintain our pool because he noticed that it’s quite filthy already. Well, you made a pretty good point that chlorine must be properly maintained so it will be safe for the swimmers. It also never occurred to me that the UV rays have the ability to break down the chlorine.

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