Poolsure Knowledge Articles

Chemical Controller Basics

A chemical controller helps keep your pool’s pH and ORP within an ideal range, reducing both overall chemical usage and liability for your property.

This article covers:

  • What a chemical controller does for your pool.
  • How to read Poolsure’s Aquasol chemical controller.
  • Why you should never, ever, bypass the pressure switch.

Having a chemical automation system — chemical controller and chemical feed pumps — is not only a huge asset to your property; it is the industry standard for commercial pools! Poolsure strongly believes in the need for chemical automation and provides them to all of our customers as part of our Water Management Program.



What does a chemical controller do, and why is it important?

To understand the importance of a chemical controller, we need to provide a quick chemistry lesson.

In order for a pool to look beautiful and blue, a lot of chemical levels need to stay in balance. Out of these, two can change very quickly: pH and disinfectant (free chlorine) level. They are also the most important indicators of how effective your pool is at sanitizing water, which directly impacts swimmer safety and pool cleanliness. Levels of pH and disinfectant will change more quickly in pools that are smaller, have a high bather load, or are exposed to direct sunlight. 

A chemical controller system measures both pH and disinfectant levels in the water. When it detects that either level is out of range, the chemical controller will automatically feed bleach and acid into your pool until pH and disinfectant levels reach ideal ranges again. This is similar to how a thermostat tells your AC system to heat or cool your house to a preset temperature.



What are the benefits of having a chemical controller?

Reduced Chemical Waste:
A chemical controller does not continuously feed bleach and acid to your pool like an erosion feeder or a timer-controlled device. The controller feeds chemicals only when they are needed for water balance. This means that properties will save money on chemicals and leave a smaller environmental impact.

Improved Patron Safety:
Since the chemical controller balanced pH and disinfectant levels in real time, these chemical levels are balanced before they negatively impact pool equipment or patrons.

Advanced Warning:
Warning indicators from your controller may be symptoms of other problems in your pool, such as inadequate water circulation or malfunctioning pumps.

Reduced Operator Workload:
Having a chemical automation system is like having a pool operator always be there to balance your pool with bleach and acid. This automation will greatly reduce the daily workload of your pool operators or maintenance personnel.

Running an automated chemical feed system for your pool is a process that works 24/7 to help reduce chemical costs, decrease liability and risk, and create a safer, healthier swimming experience.

Running an automated chemical controller will help create a safer and healthier swimming experience.

What readings are displayed on the Aquasol chemical controller?

Our chemical controllers show two numbers and a variety of alerts. First, let’s focus on the numbers.

ORP, shown in mV, is the measure of free chlorine available in your pool for disinfection. pH is the measure of the balance between acid and base in your pool. Feeding bleach into your pool is what causes free chlorine to form. Adding more bleach will cause pH to increase; adding pool acid will bring the pH back down. Both ORP and pH together tells us whether the pool water is currently balanced.

The ideal pool has a pH reading of 7.4 – 7.6 and an ORP reading of 700* – 800.

* The lower bound of ORP is 650 in Texas, but 700 in Florida.

When the chemical controller detects something wrong, it will display an alert next to the ORP or pH reading. For example, if the chemical controller has been feeding chemicals continuously into your pool for four hours, it will stop and display a feed limit alert. This will give someone a chance to see if another problem in the pool might be preventing the water from becoming balanced.

We will explain alerts in another article dedicated to troubleshooting chemical controller alerts. In the meantime, if you an immediate question regarding your chemical controller, please contact our customer service department through chat, phone, or by filling out the contact form.

Aquasol's chemical controller will display an alert whenever it detects an issue.

What is a pressure switch, and what does it do?

While the central part of Poolsure’s chemical feed system is the chemical controller, another essential part is the pressure switch.

The pressure switch is the chemical controller’s safety switch. If it detects insufficient water flow in the pool return pipe at the point of chemical injection, it will prevent the controller from feeding chemicals.  The controller will only feed chemicals into the pool if the incoming water pressure is 1-6 psi*. This helps prevent chlorine and acid from mixing in the return pipe during periods of low or no flow which can lead to the creation of chlorine gas. Chlorine gas can be toxic to swimmers and anyone around the pool.

* Special versions of this pressure switch are available for when higher pressure sensing is required due to higher static head pressure (ex: if a pool built above a pump room).

A chemical controllers safety switch will detect insufficient water flow and act accordingly.


The pressure switch interrupts the chemical controller if it detects low water pressure, which usually indicates that there is a problem with your pool’s circulation. If this happens, you should check to see whether your pool filter needs to be cleaned or changed. While the circulation issue persists, it is unsafe to feed chemicals into the pool. Bypassing the pressure switch will immediately lead to unsafe swimming and working conditions in the pool area. 

We highly recommend watching this video, produced by the American Chemistry Council, about pool interlock safety for more information about the importance of the pressure switch safety feature: Preventing Unintended Chemical Injection

Poolsure’s parent company Aquasol designs and produces chemical automation equipment. Because of our expertise, we use and service our own proprietary chemical controllers and can personally ensure their quality and function. As part of our Water Management Program, a controller is installed for every body of water on your property, ensuring that all of your pools have a safeguard against unexpected chemical imbalances.

Pools can be unpredictable. With a chemical controller, you are already on your way to getting them under control!

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