Commercial · 5 min read

How Automated Chlorine and pH Control Works

Automated chemical dosing uses sensors to measure water chemistry and dosing pumps to maintain sanitiser and pH levels. Here is how it works.

The basic principle

Automated chlorine and pH control continuously measures the pool water using sensors, then doses chemicals as needed to keep the water within set parameters. This reduces manual testing and helps maintain consistent water quality.

Sensors and probes

The system uses probes to measure key parameters:

• pH probes monitor acidity

• ORP (oxidation-reduction potential) probes indicate sanitiser effectiveness

• Free chlorine sensors measure actual chlorine levels (in advanced systems)

• Temperature sensors support compensation and logging

These probes are installed in a flow cell where pool water passes continuously.

The controller

The controller reads the sensor data and compares it to your set points. When a value drifts outside the target range, the controller activates a dosing pump to add the required chemical — acid for pH, chlorine for sanitisation, or CO₂ as an alternative pH reducer.

Dosing pumps

Peristaltic or solenoid dosing pumps deliver precise amounts of chemical from a storage drum into the return line. The controller determines how long the pump runs based on how far the reading has drifted from the set point.

Why automation matters for commercial pools

Manual dosing in a high-use commercial pool is labour-intensive and prone to overshoot or undershoot. Automated control maintains tighter tolerances, provides a logged history of water chemistry and reduces the risk of unsafe water conditions.

Ultra Automation provides assessment, installation and commissioning support for commercial chemical dosing systems including Aquarius ULTIMA and GRANUDOS Touch.

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