Guide to Automatic Pool Chlorinators

A pool without a chlorinator is akin to an algae-ridden frog pond. I know that does not sound incredibly tempting to swim in, which is why I highly recommend an automatic pool chlorinator to help you keep the right chemical balance in your pool and safe for swimming.

It may sound like a nice option, but having a pool without the use of chlorine to keep it clean is inviting a host of bacteria into your water, as well as some local amphibians that would love to pull up a lily pad and hang out.

Below, I walk through how chlorinators work, the different types you can choose from, the pros, cons, and more.

Why Use a Chlorinator in Your Pool?

While some people try to keep their pool chlorine-free, this is not advisable. Chlorine helps to kill water-borne germs that often make swimmers sick with ailments such as diarrhea, ear infections, and various skin infections. While chlorine is not the only way to disinfect a pool, it is a tried and true method that will cover the basic threats to your pool’s cleanliness.

The key to using a safe amount of chlorine is to regulate it by using an automatic chlorinator. Maintaining the appropriate chlorine level keeps the chemicals from building up and causing skin irritation, eye redness, or other unpleasant side effects.

While you shouldn’t be ingesting large amounts of chlorinated pool water, it’s worth noting that excess chlorine can be caustic to your insides, too. Exposure over time can also be harmful to your body systems, whether you’re taking splashes to the face or are soaking in the pool for hours.

It is essential to keep your chlorine levels between 1.0 and 3.0 parts per million to maintain a clean and well-balanced swim environment.

To keep your pool running optimally, you will need an automatic pool chlorinator to make your life a little easier. Choosing a chlorination method for your pool is not as easy as going and grabbing the first one that looks good. There are a few things you need to know before choosing a pool chlorinator, so I have added some information below to make it a little easier for you to decide.

What is a Chlorinator and How Do They Work?

While there are other ways to add chlorine into your pool, such as using chlorine tablets or an approved liquid chlorine method, an automatic pool chlorinator makes your job a lot easier. An automatic pool chlorinator is a handy piece of equipment that automatically dispenses the proper amount of chlorine into your pool, depending on your chosen method.

To use an automatic chlorinator is pretty easy, but you will need to know how to do it properly so that your pool is getting the right amount of chlorine for its size. You plug your automatic chlorinator right into the pump and pool filter system, and from there, it cleans the water returning to your pool.

Types of Pool Chlorinators

There are two different types of automatic chlorinators, inline and offline. Both cost about the same, and work much the same, as well. The big difference is how they are installed. To find out which one is right for you, we’ve included a bunch of details below. If you have a salt water pool, check out my guide on salt water chlorine generators.

Inline Chlorinator

An inline chlorinator is plumbed into the PVC pipe. Water passes through the chlorinator, dissolving some of the chlorine tablets and dispersing the appropriate amount needed into the water. For inline chlorinators, you will want to have this hard plumbed in when your pool is constructed or during a pool renovation so that getting to the PVC for cutting is not a huge undertaking.

The inline chlorinator makes it a much sturdier option and has fewer parts to replace. It’s way better bang for your buck and well worth looking into.

Offline Chlorinator

If you already have an existing pool and massive construction isn’t an option, then an offline pool chlorinator is the option you want to go. With an offline chlorinator, you will not need to cut a piece of the pipe. Instead, you will only need to put small holes in the PVC plumbing. An offline chlorinator is a good option when there is little room left to install the chlorinator.

Automatic Pool Chlorinator vs. Automatic Chemical Feeder

Automatic chemical feeders are similar to automatic chlorinators. A chemical feeder typically works with chlorine and bromine, whereas chlorinators only work with chlorine.

Automatic Pool Chlorinator Brands

There are several different types of pool chlorinators to choose from, varying in size, functionality, and installation techniques. A few brands to look into are:

Hayward Chlorinators

There are various sizes available in this chlorinator, both inline and offline, so the choice is there for most sizes of residential pools whether you have an inground pool or above ground pool. The 9lb tablet capacity puts it in the top rankings for larger residential pools.

Pentair Chlorinators

The Pentair chlorinator provides quality performance to keep your pool clean, as they are built with flow-through circulation for maximum quality output.

Sani-King Chlorinators

Double unions make removal easy for storage and cleaning. Various sizes of chlorinators allow you to find an option right for your pool and your needs.

CMP Chlorinators

Has a clear top that makes it easy to check the tablet levels. There is also a flow level monitor on the side of the device for your convenience.

Pros and Cons of Automatic Chlorinators

Of course, you can always take the time to go around your pool and add chlorine tablets along the edges. But an automatic pool chlorinator is a much easier way to go about ensuring the sanitary needs of your pool. There are a few pros and cons to using automatic pool chlorinators, and we’ve listed them so that you may better decide which route to go.


  • Prevents staining of chlorine tablets on your pool lining
  • You can set the chlorination levels automatically
  • Option to install offline or inline
  • Can be used on both above ground and inground pools
  • Works even when you are away from home


  • The cost will set you back more than adding tablets yourself
  • Requires upkeep and may need repair over time
  • Installation may be difficult if your pool is pre-existing

How To Choose A Chlorinator

It is imperative that you take the following into consideration when you are choosing a pool chlorinator so that it works effectively to sanitize your pool:

  1. Take the size of your pool into account as you will need a chlorinator that can service the amount of water the pool holds.
  2. Decide on a budget before you begin to look so you know a price point going in.
  3. Consider the accessories that the chlorinators come with, as that will affect installation. These sizes of pool chlorinators also vary greatly, so you will want to know the space you will need for installation.

What Type of Chlorine to Use in a Pool Chlorinator

There are various forms of chlorine you can use in a pool chlorinator: chlorine tablet, stick, liquid chlorine, or granules.

For an automatic pool chlorinator, you will most likely want to use a chlorine tablet or stick as these need to be changed less frequently than liquid chlorine, giving you more time between upkeep.

It is also worthy to note a chlorine tablet on your hands may cause a reaction and be unpleasant in general. I include this as a small but significant reason for choosing an automatic chlorinator.

How to Set Your Chlorinator Rate

In order for your pool to reap the benefits of a pool chlorinator, you will need to know how to set chlorine levels. There are a few steps you need to take in order to set your chlorinator rate properly.

  1. To know how to set your chlorinator rate, you will need to know your pool volume to release the correct amount of chemicals into the water. For this, you will want to make sure that you have bought the correct chlorinator for your pool size. If you do not know your pool size, you can figure it out relatively easily by using my pool volume calculator.
  2. Once you are sure that you have the correct size of chlorinator, I recommend that you set the output at 50% for two to three days and see how the chlorine levels in your pool are. Test the levels to see how clean the water is or if there need to be adjustments. From there, you can adjust the setting according to what your pool needs.
  3. You want your chlorine levels to be one to three parts per million. You can then adjust according to the levels. If the chlorine levels are too high – lower the percentage. If the chlorine levels are too low – increase the percentage. It’s an easy thing to do. Just keep an eye on the levels consistently over time to ensure your chlorinator is still working to its full ability.

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Final Thoughts

It’s important to remember that while an automatic pool chlorinator is a bit of a financial investment, in the long run, it will save you a ton of time on pool maintenance and allow you to spend more time enjoying your fresh, perfectly balanced pool. There is also the benefit of not smelling like chlorine after dropping tablets into your pool. Plus, when it comes to saving time, an automatic chlorinator is worth the up-front investment.

Questions? Let me know!

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