Automated Dosing: Halo Chlorinator + ORP & pH Probe Installation
At My Pool Shop Melbourne, much of the most important pool work happens out of sight like inside plant rooms and plumbing lines where water treatment systems do their job every day. While pool owners often focus on the water they can see, it’s often the setup behind the scenes that determines how consistent, safe and easy a pool is to maintain.
Recently, our team completed an upgrade to a pool’s chlorination system, installing a new Halo 25 chlorinator with ORP and pH probes, as well as an Astral P320 variable speed pump. This project is a great example of the care and planning that goes into modern automated pool systems, and why doing it properly makes a real difference to water quality. In this case, changes to the existing plumbing were required, along with careful planning around flow rates and sensor placement to ensure accurate readings and reliable performance. It’s a practical example of how thoughtful system design and experienced installation help create cleaner water, fewer problems and simpler pool maintenance.
The Existing System & Limitations
Before Lachlan arrived, the pool was running on an older INSNRG chlorinator and pump, which had stopped working. The existing system had no ORP or pH probes, meaning there was no automated dosing system prior to the installation.
The plant room was compact, leaving little room for new equipment, and the existing pump had become significantly de-levelled over time, something that can cause long-term damage to plumbing over time if not corrected. On top of that, the customer wanted a system that could be expanded in the future for further automation, so we needed a solution that was flexible and modular, without requiring a full plumbing rebuild.
Choosing the Right Equipment
For this project, Lachlan installed a Halo 25 chlorinator and an Astral P320 variable speed pump, sized for a 40,000–50,000-litre pool. This system was chosen because:
- It’s compatible with automated dosing systems, allowing automated control over chlorine and pH.
- It’s modular, so extra equipment can be added over time.
- It consolidates multiple functions in one system, reducing complexity for the pool owner.
- The variable speed pump means the customer can save on energy costs over time.
The choice of equipment ensured the pool could be upgraded now while leaving room for future enhancements without major disruption or cost.
Smart Plumbing and System Design
Even with a compact plant room, Lachlan aimed to reuse as much of the existing plumbing as possible to keep costs down. The main adjustments included:
- Re-leveling the pump to ensure proper operation and prevent future damage to plumbing.
- Adjusting the pump inlet height to match the new equipment.
- Finding a practical location for the probe mixing cell and acid dosing system that would remain accessible for future cleaning and maintenance.
Pro Tip: Good system design isn’t just about fitting equipment, it’s also about ensuring serviceability. Leaving enough room for access now saves time and headaches later. For this project, Lachlan’s focus was on where he could put equipment so that it could be serviceable and probes could be easily accessed for future cleaning and replacing if needed.
Probe Placement: The Key to Accurate Water Control
Installing ORP and pH probes might sound simple, but placement is crucial for accurate readings and reliable dosing. On this installation:
- The ORP and pH probes were positioned to receive consistent water flow before the mixing cell. Ideally, they must always be installed after the filter to ensure they stay healthy and accurate.
- The acid feed mixing cell was installed after the probes, ensuring proper chemical contact.
- The temperature sensor was placed before the solar bypass, so it measured average pool water temperature and not just water returning from the roof solar system. An accurate average pool temperatuire reading is needed for accurate ORP management.
Probes must also be installed horizontally to stay submerged when the system is off, protecting them from drying out and ensuring long-term accuracy. Avoiding turbulence and air locks is equally important, which is why careful planning of the flow path is essential. To avoid turbulence, Lachlan ruled out the possibility of probe installation between the inlet and outlet of the solar bypass.
Installation Challenges and Problem Solving
For this installation, one of the most difficult parts for Lachlan was planning where all the new equipment would fit, from the chlorinator to the mixing cell, acid dosing and temperature probe. Lachlan didn’t expect to have to re-level the pump, but it is something that we always check when installing new equipment, ensuring it is installed level and stable so as not to damage plumbing over time
This is a great example of why experience matters. Small adjustments on-site, like leveling the pump or choosing the right location for probes can have a big impact on the longevity and performance of a pool system.
Bonus Insight: While on site, Lachlan identified broken pool lights and noted that with the new Halo system installed, there’s an opportunity to integrate lighting control into the same platform using the Halo Lite, rather than replacing the end-of-life transformer. The option was discussed and the information was passed on to the service coordinator to help prepare indicative pricing for any future upgrades.
Commissioning the System & Performing Checks
After the Installation, Lachlan performed a series of checks before handing over the system where he:
- Ran the system and pump to confirm priming and leak-free operation.
- Calibrated ORP and pH probes.
- Primed the acid feeder to remove air bubbles.
- Tested the chlorinator at maximum output to ensure sufficient chlorine production.
- Walked the customer through operation, maintenance and tips.
Maintenance Reminder: Automated dosing systems are not “set-and-forget.” Probes need periodic cleaning and recalibration, feeding tubes and hoses require replacement over time, and acid must be diluted properly to prevent equipment damage. Keeping stabiliser (cyanuric acid) levels below 30ppm is also critical to reduce any interference with probe accuracy.
Benefits of an Automated Dosing System
Automated ORP and pH systems provide several advantages over manual dosing methods:
- Precise chemical dosing prevents under- or over-treatment, keeping water safe and reducing chemical waste.
- Stable pH levels improve chlorine effectiveness and reduce swimmer discomfort.
- Reduced manual handling of chemicals lowers the risk of accidents.
- Continuous monitoring ensures water quality stays consistent, even with fluctuating pool use or weather changes.
In short, the system keeps water cleaner, clearer and healthier, while making pool maintenance simpler for the owner.
Why Choose My Pool Shop Melbourne
Upgrading a pool system isn’t just about new equipment, it’s about making sure everything works together for clean, safe and easy-to-maintain water. Careful planning, precise probe placement and smart plumbing adjustments all play a role in keeping water balanced and reducing chemical waste.
At My Pool Shop Melbourne, our team takes care of these details so pool owners can enjoy worry-free swimming. Every installation is tailored to the pool and the owner’s needs, ensuring equipment performs efficiently now and in the future. If you’re considering a pool upgrade, get in touch with our team today. We’re here to help you every step of the way, “because everybody deserves a safe and healthy pool”.
