An In-depth Guide to Automatic Pool Chlorinators: Inline and Offline

This article will cover two types of automatic pool chlorinators, inline and offline. Learn about how they work, how to install them, what the main differences are between the two, and much more.

Say goodbye to the weekly chore of manually adding chlorine to your pool and say hello to an automatic pool chlorinator! This is the future—untie the cord and enjoy a more natural, chlorinated, and healthy pool.

Automatic pool chlorinators require little upkeep and are inexpensive in comparison to other means of water sanitization. The best part? You get additional protection for algae or bacteria growth.

If you’re looking for a way to make your summers easier while keeping up with EPA regulations, this is the perfect solution. Plus, you save money on that pricey green pool kit when you finally decide to use pool chlorinators. But what exactly is an automatic chlorinator?

Read on for a thorough guide on automatic pool chlorinators. 

What is an Automatic Pool Chlorinator?

Pool Chlorinator Outside

An automatic pool chlorinator is a device that automatically mixes chlorine into the water in response to various sensors. These sensors can indicate the necessary amount of chlorine for healthy swimming. Once these sensors are activated, the device can add the precise amount of chlorine needed to balance pool chemistry.

This is a much more comfortable method than maintaining your pool and dealing with constant manual additions. Automatic chlorinators are especially beneficial to those in areas where chemical usage is heavily regulated or even outlawed and pose a threat to the environment. 

What Type of Chlorine Does an Automatic Pool Chlorinator Use?

Chlorine Tablets on Pool

Pool chlorines come in 5 various forms: tablet, granules, powder, liquid, and gas. Automatic Chlorinators mostly use chlorine tablets or sticks. However, while chlorinators are made for chlorine, chemical feeders, on the other hand, usually work with both chlorine or bromine.

Keep in mind that automated chlorinators and automatic chemical feeders can operate with various different-sized tablets or sticks, depending on the instructions provided.

Two Types of Automatic Chlorinators

Inline automatic chlorinators and offline automatic chlorinators are the two types of automatic chlorinators available. Both are almost the same in terms of cost and performance.

The main difference is how they are installed. Read on to find out which one is best for you based on the information we’ve provided below.

Inline Chlorinator

An inline chlorinator is connected to the PVC pipe. Water flows through the chlorinator, dissolving the chlorine tablets and dispersing the proper quantity of chlorine into the water.

However, when installing inline chlorinators, you would want this hard piped in during the construction of your pool or a pool restoration so that getting to the PVC for cutting is not a major job.

Offline Chlorinator

If you already have a pool and don’t want to go through the hassle of a full-scale pool renovation, then an offline chlorinator is your best option. With an offline chlorinator, you won’t have to worry about cutting a portion of your pipe.

As an alternative, you will just have to put a few holes in the PVC plumbing. Also, an offline chlorinator is a space saver option, especially if there is little room to install a pool chlorinator.

Advantages and Disadvantages of Automatic Pool Chlorinator

Pool Chlorinator
A floating Pool Chlorinator is a chlorine dispenser that floats on the water’s surface

Buying a pool chlorinator is simple yet one of the most important decisions you will make for your pool. There are multiple advantages to having one of these machines in your swimming pool. However, there are also multiple disadvantages that you need to be aware of before you can make an informed decision.

With that being said, let’s take a look at some pros and cons of pool chlorinators so that you can decide whether this sound investment is worth it for your pool.


  • Even while you’re gone from home or out of town, the pool chlorinator continuously operates automatically. You don’t have to worry about correcting the flow and checking the chlorinator’s levels. It will run itself so that you don’t have to worry about it.
  • You can save money with automatic pool chlorinators. The machines does not need too much maintenance and should work automatically for months without needing you to even check on them.
  • You can use automatic pool chlorinators in salt and fresh water pools. 
  • Some smaller automatic pool chlorinator machines come in 2 and 3-gallon sizes that don’t require a filter pump. This will save space beside the size of the actual device needed for the system to function.


  • It is a little more expensive than manually applying chlorine.
  • Some automatic pool chlorinators are a little more sensitive to outside water conditions. This means they need “regular” chlorine to keep them working properly.
  • Some automatic pool chlorinators have a noticeable amount of pump noise while they’re running.
  • It can be challenging to install correctly.

Setting up Pool Chlorinator Rate

Under the Pool

The amount of chlorine you will add to the pool chlorinator depends on the volume of your pool. So you have to know your pool volume before you can set the chlorinators’ dispersion rate.

You’ll also want to be sure that the chlorinator you choose can handle the volume of your pool. Some are designed to disinfect 10,000-gallons of water, while others can sanitize pools as large as 40,000 gallons of water.

Important note: If you purchase a chlorinator too tiny for your pool, the water will not be adequately sanitized, so be sure you get the correct size.

Once you’ve determined the volume, follow the manufacturer’s directions to set the chlorinator’s dispensing rate.

Bottom Line

There are several types of automated pool chlorinators out there, some of which do not apply chlorine properly. Always make sure you do your due diligence and research the brand of chlorinator to make sure it’s one that you can rely on.

Check out our collection of interesting pool articles. These tips can help you keep your pool clean and maintained. Take your family out to a clean, safe pool and have fun!

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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