How to Protect Your Auto-Dosing Equipment
Auto-dosing equipment isn’t ‘set-and-forget’, like all pool equipment they require regular maintenance so they can work efficiently and provide maximum benefit. Your exact maintenance routine will depend on your brand of auto-dosing equipment, so it’s important to read your manual before performing any maintenance.
Generally speaking, looking after an auto-dosing or probed system involves a combination of:
- Cleaning & Recalibrating Sensors/Probes
- Inspecting Supply & Squeeze Tubes for Signs of Wear
- Checking & Adjusting Output Settings
We know these systems can seem complicated and that it may have come as a suprise to you that they require upkeep. But don’t worry, we’re here to make things simple!
Understanding How Your Auto-Dosing System Works
Before getting into maintenance, it helps to know the different components of an auto-dosing system and understand their functions. Most systems dose liquid acid but some, such as the Astral EQ and Halo have a saltwater chlorinator for chlorine dosing, and others like the Astral RolaChem dose liquid chlorine. The Chemigen system can be set up for either salt water or liquid chlorine or both (but that is unlikely for most domestic pools). A dosing unit is made up of several key components that work together:
- Dosing Pumps: deliver precise amounts of chemicals
- Solenoid Valves: control the flow of chemicals
- Tubing: carries chemicals from the drums to the system
- Sensors (pH and ORP probes): monitor water balance
- Control systems: manage how and when chemicals are dosed
The above diagram is of a typical Chemigen setup, each of these components plays an important role, and because they are constantly exposed to water, chemicals and moving parts, they will naturally experience wear over time. Regular checks help identify small issues early before they turn into larger and more expensive problems. Astral Pools recommends performing the following maintenance checks. The table below is from the Astral eQulibrium manual which uses a salt chlorinator rather than a liquid chlorine doser. Remember to always check your equipment manual for recommendations specific to your auto-dosing equipment’s make and model.
Astral Viron EQ Installation and Operating Instructions
1. Cleaning & Calibrating your ORP & pH Probes
While Astral Pools recommends calibrating your probes every six months to ensure chemical delivery is as accurate as possible, there are other indications you may need to clean and recalibrate your probes that we see in our store. One of these is if the pH and ORP reading points on your system are reading differently to what your in-store water tests show. If this is happening regularly, you may need to recalibrate your probes more often.
Calibration involves cleaning the probe with a cream non-abrasive cleaner then using dedicated test solutions to recalibrate. We sell a ‘Probe Calibration & Cleaning Bundle’ in our store which includes a probe cleaner as well as ORP and pH solutions. We have also prepared an instructional pamphlet which can be followed for an Astral or a Chemigem unit. It is important to read your auto-dosing equipment manufacturers instructions on cleaning and calibrating your system’s probes as certain models require calibration fluid of a specific level and may have different cleaning procedures.
2. Checking for Leaks and Tube Condition
Because auto-dosing systems rely on tubing to transport chemicals, keeping an eye on these components is essential. Over time tubing will harden, crack and/or become opaque. They may even leak at connection points, so periodic inspections will help identify any problems early so your auto-dosing equipment can dose chemicals effectively.
Inspecting and Replacing Squeeze Tubes
The squeeze tube is a key component inside the dosing pump and is subject to regular wear due to its constant movement and the fact it is ‘squeezed’ by the pump to draw the fluid through (hence the name). To inspect it, you can remove the cover. There should be a layer of silicone lubricant over the tube and you can observe whether it appears flat. If it does, it may need replacing.
3. Checking & Adjusting Output Settings
Once your probes are clean and calibrated, it’s important to ensure your system is dosing the correct amount of chemicals. Auto-dosing systems rely on pH and ORP setpoints or targets which the unit tries to maintain and you should be able to see the actual readings as well as the setpoint on the front panel. If the setpoints are incorrect, your chlorine or pH levels may be too high or too low. A good approach is to compare your system’s actual readings with an external water test and look for consistent results between them.
Ideally the actual readings will match the setpoint, however there are times when they aren’t the same. Don’t stress straight away as the system needs time to recover. Essentially the level has to be out before the system can correct it so give it at least a cycle or two. If you find the actual readings are too high or low best take a sample to the pool shop for testing. You will always need to know what your ‘actual’ readings are versus the ‘setpoint’ so ensure you take a note of these with you to the pool shop. This allows us to better evaluate problems and recommendations for adjustments.
When making changes we recommend making small, gradual adjustments and allowing time for the system to respond, rather than making large changes all at once. Regularly reviewing these settings is especially important after changes in weather, pool usage or water chemistry, as these factors can all affect how much chlorine and acid your pool needs.
Diluting Hydrochloric Acid
You must check your equipment manual to see what level you need to dilute acid before connecting it to your auto-doser. Systems are designed to operate at specific concentrations and using full-strength acid may lead to overdosing (acidic pool water) and premature wear of your auto-dosing equipment using under strength acid may mean your system can’t keep up.
Chemicals drums should be stored at least 1 metre horizontally from the control unit in a well ventilated area to avoid corrosive damage. Failure to do so would likely void the equipment’s warranty so make sure you refer to your manufacturers manual. The diagram below has been taken from Astral’s ‘Halo pH Dosing Installation Manual’.
**HYDROCHLORIC ACID AND LIQUID CHLORINE ARE CLASS-A CORROSIVES. WHEN DILUTING REMEMBER TO ALWAYS ADD WATER TO THE DOSING DRUM FIRST BEFORE ADDING ACID. WHEN HANDLING CHEMICALS, ALWAYS WEAR APPROPRIATE PPE SUCH AS CHEMICAL RESISTANT GOGGLES & GLOVES, A RESPIRATOR, SAFETY FOOTWEAR & OVERALLS (AS SPECIFIED IN THE SDS SHEETS LINKED BELOW) **
https://www.poolpro.com.au/sds/
Why Regular Maintenance Matters
Auto-dosing systems operate in a demanding environment. They are constantly exposed to moving water, chemicals and pressure, all of which contribute to gradual wear over time. Some components will naturally wear as part of normal operation, but regular checks allow you to identify these early and replace them before they cause larger issues.
A small amount of ongoing maintenance will:
- Improve accuracy of chemical dosing
- Extend the life of your equipment
- Reduce the likelihood of breakdowns
- Help maintain safe and balanced pool water
If you’re unsure about any part of the process, or if your auto-dosing system isn’t behaving as expected, bring a water sample to the store and ask our retail team for advice or our service team can come to test & check your system & clean and calibrate your sensors. Whether it’s advice, testing or replacement of parts, we’re here to help you keep things running smoothly, “Because everybody deserves a safe and healthy pool“.
