Unstabilized Chlorine and Stabilized Chlorine Explained

What’s not to love about a new pool or tub? Warm soaks to literally warm you from the inside, the chance to unwind and lots of TLC! However, owning a new pool or tub doesn’t just come with the roses; it, like everything in life, comes with the thorns too—cleaning, maintenance, so on and so forth.

One of the aspects of pool owning that many folks find especially thorny is all the different chemicals that you require to keep your pool in top shape and one of the first chemicals you’ll need to learn about is chlorine and its two types – stabilized and unstabilized.

Here’s a 101 on stabilized and unstabilized chlorine to help you take your first step towards pool chemicals!

unstabilized chlorine vs stabilized chlorine

Unstabilized Chlorine

Stabilized chlorine is stabilized because of a certain compound called cyanuric acid. This acid not only stabilizes chlorine but also makes it remain longer in the pool water, by preventing ultraviolet rays from the sun from eating up the chlorine.

Therefore, unstabilized chlorine is as simple as chlorine without the cyanuric acid. This chlorine dissipates faster and doesn’t sanitize as strongly as stabilized chlorine, which means you’ll have to keep replenishing the amount in the water.

So with so much working against its favor, why do we need unstabilized chlorine at all? Well, unstabilized chlorine is necessary for the following reasons:

  • It’s a good “shocking” agent.
  • It’s a quick fix for chlorine levels when your pool is working overtime.
  • Since UV rays are the problem, you can use unstabilized chlorine in indoor pools without any worry!

It’s necessary to bear in mind that without a stabilizing agent, the chlorine in your pool won’t stay in the water for too long. Therefore, it’s necessary to frequently check the water and ensure that the chlorine level stays at 3 parts per million (PPM). You’ll have to keep adding chlorine to maintain this figure.

Stabilized Chlorine

No prizes for guessing this one – if you’ve been paying attention, you know that stabilized chlorine is simply chlorine with cyanuric acid in it! As mentioned earlier, cyanuric acid protects the chlorine, keeping it in your pool much longer and ensuring that it’s always working to the best of its ability.

If you’re using stabilized chlorine, you don’t have to worry as much about your pool’s cleanliness, frequent checks to ensure the chlorine level is right and constantly adding chlorine to the pool to maintain the ideal level, as you probably would with unstabilized chlorine.

Therefore, stabilized chlorine is sworn by for the following reasons:

  • You save a ton of money by not having to constantly buy chlorine.
  • It reduces the amount of chlorine used in the pool without any compromise on the safety of the pool.
  • It means less time, money and effort invested.

However, stabilized chlorine isn’t all as perfect as it seems to be. Extremely high levels of cyanuric acid render the efficiency of the chlorine useless, which naturally, is counter productive.

To combat excess cyanuric acids in your pool, you’ll have to dilute the water till the ideal level is reached.

What Type of Chlorine to Use?

Since it’s all chlorine at the end of the day, does it really matter which type of chlorine you use in your pool? Long story short, yes, but this depends on what kind of pool you have.

Unstabilized chlorine is excellent for indoor pools and is a great shocking agent. If you have an outdoor pool and don’t want to spend a fortune in terms of money and time on maintaining your pool, stabilized chlorine is a must. (In case you’re using unstabilized chlorine, you can add cyanuric acid – just keep sure the level is less than or equal to 100 PPM).

The Bottom Line

All said and done, though, whether you’re using stabilized or unstabilized chlorine, it’s important that you use chlorine!

Your pool needs to be swimmable in, sanitized and clean at all points and both stabilized and unstabilized chlorine will help you with these needs. Therefore, it all comes down to what you’re more comfortable with and what your pool actually needs.

Now that you know the what, why, pros and cons of stabilized and unstabilized chlorine, educate yourself on the other chemicals that your pool or tub needs, to have a safe, healthy and clean tub.

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years experience in pool care, plant care and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!