Stabilized vs Unstabilized Chlorine

Stabilized Vs Unstabilized Chlorinev pool water treatment

One of the questions pool owners get asked the most is what’s the difference between stabilized vs unstabilized chlorine?

Well, I’m glad you asked because I’m finally gonna answer that…

which one should you use & what’s the difference between them.

let’s find out.

First talk about Chlorine.

What is chlorine?

Chlorine is a sanitizer. it is a halogen-based sanitizer and one of the most popular & effective sanitizers for swimming pools.

Normally, we wanna keep our chlorine level in the pool between 1-3 parts per million.

If you have a normal pool or a saltwater pool, both of those should stay roughly around 3 parts per million of chlorine at all times to make sure that your pool is completely sanitized.

Now there are two different

types of chlorine, there is… stabilized and unstabilized chlorine.

Stabilized Vs Unstabilized Chlorine – Comparison

In this section, I will explain the difference between stabilized and unstabilized chlorine in detail.

What is Unstabilized Chlorine?

Unstabilized chlorine is generally just chlorine, it is the normal form of chlorine. It is called unstabilized because when you add it to your pool, the UV rays of the sun will burn off the chlorine very fast.

Chlorine that’s unstabilized tends to come in a powder form or a granular form. 

Similar to shock or just like chlorine granules, that you would throw directly into the pool. In fact, if you buy something called shock, then it’s probably unstabilized chlorine.

You wanna check the label because there are so many different types of shocks out there. But commonly, the best shock for pools is unstabilized chlorine.

Unstabilized form of chlorine is susceptible to the sun burning it off. There is no protectant in it.

while on the other hand exactly opposite of unstabilized, stabilized chlorine protects it from being burned off by the sun.

Not 100%, but it protects it. Now, the question is…

Why would you add unstabilized chlorine to a pool if the sun’s just gonna burn it off?

Well, typically you would add it because you want the sun to burn it off, meaning it’s a short burst effect of chlorine that you’re trying to add to the pool. You want it to be super high.

shocking is really just a simple method of chlorination. When you add shock to a pool or a bunch of unstabilized chlorine to a pool, you are raising the chlorine level of the pool to a very, very high level, which is killing bacteria and oxidizing the current chlorine that’s in there. This process is called the shocking of the pool.

Typically, shock or any granular chlorine is unstabilized chlorine, meaning that it is susceptible to the sun.

This is the reason why all pool water treatment experts recommend shocking the pool at night because at that time sun isn’t present and it does not burn off the chlorine you added to the pool. In this way, you can chlorinate your pool for a long period of time.

What is Stabilized Chlorine?

Well, the simple answer is it’s the opposite of unstabilized chlorine. It usually comes in the form of a tablet. These chlorine tablets for pools have an active ingredient called trichlor.

This means it has cyanuric acid in it, which protects it from being burned off by the UV rays of the sun.

You can use stabilized chlorine to keep the chlorine at around 3 parts per million at all times, and the stabilized chlorine usually lasts about three to five times longer than unstabilized chlorine.

When you add these pucks to your pool, via a chlorine floater, within your skimmer basket, or what we recommend is to add them to an automatic chlorinator, that is your best bet for adding chlorine pucks and keeping the water at 3 parts per million in a classic chlorine pool.

But if you’re adding chlorine pucks or chlorine tablets, and they are stabilized, because they’re trichlor, then it is adding chlorine stabilizer, or cyanuric acid to your water, in very, very low amounts because it is stabilized chlorine, that’s what that means.

Either way, you’re gonna add chlorine stabilizer or cyanuric acid to your water, whether you’re using just unstabilized chlorine or a mix of unstabilized and stabilized chlorine,

just to make sure that both of those things are kind of stabilized together, and you wanna keep your cyanuric acid at a very specific level.

You wanna keep the cyanuric acid between 30 and 80 parts per million.

Ideally, you wanna keep the cyanuric acid level at around 50 parts per million.

If your cyanuric level goes too high, it can cause problems with your sanitizers. Speaking of chlorine, and the only way to lower cyanuric acid is to dilute your pool water.

Okay, so hopefully you know the difference between stabilized and unstabilized chlorine,

it’s pretty simple.

Now, The final question is…

Which One Should I Use?

If you have an outdoor pool, you’re gonna use a combination of both unstabilized and stabilized chlorine.

Unstabilized chlorine for shocking and high-chlorination, for oxidation in your water and stabilized chlorine for just general, you know, keeping your pool at around 3 parts per million, because it’s just last longer with the tablets, and they’re easier to add than constantly adding unstabilized chlorine to your pool.

Now, if you have a saltwater pool, you are constantly adding unstabilized chlorine to your pool, and you can use cyanuric acid to help the sun not to burn off the chlorine that you’re generating.

And whenever you super-chlorinate it, again, you’re just adding a bunch of unstabilized chlorine to the pool, because you’re not generating cyanuric acid with a saltwater system, you’re gonna need to add that separately.

If you have an indoor pool, you really are not bothered by the UV rays of the sun too much if you have a, you know, a cover, if you have the sun peeking through, well then, you’re gonna have to worry about it, and if you have an indoor pool, I recommend keeping your cyanuric acid, or your chlorine stabilizer level, at around 10 parts per million.

I Hope, this stabilized vs unstabilized chlorine comparison post is helpful to understand the difference and clear all your doubts.

Water Treatment Basics