Water Test Parameters

Water Test Parameters at Poolwise

At Poolwise we use a generic set of target ranges for the main tests we conduct. These ranges are based on what is generally acceptable for most residential swimming pools in Western Australia.

However, some pool builders, pool painters, resurfacers and installers specify water parameters that are slightly different in order to protect paintwork, gelcoats or other finishes. In these cases, their instructions always take priority.

On your first test, we ask that you provide us with any written water parameter requirements you have received from your builder, painter or installer so we can enter these into our system. Our default target ranges are a very good general guide, but it is important that we review any specific instructions at your first appointment and adjust where necessary.

Please compare the target ranges below with the information supplied by your pool builder, painter or installer and follow their recommendations if they differ.

Our Default Target Ranges

pH

Our default pH range is 7.2 to 7.6.

In some situations, it may be necessary to keep pH at the lower end or the upper end of this range, depending on your pool surface and equipment manufacturer's advice. Maintaining pH within this range helps protect pool surfaces, equipment, and swimmer comfort. pH that is too low can cause corrosion of equipment and surfaces, while pH that is too high can reduce chlorine effectiveness and cause scale formation.

Total Alkalinity

Our default total alkalinity range is 80 to 250 ppm.

This range can and does change according to pool builder or equipment manufacturer instructions. Total alkalinity acts as a buffer for pH, helping to stabilise it against rapid changes. Low alkalinity can lead to pH bounce and corrosive water conditions, while very high alkalinity can make it difficult to adjust pH and may contribute to cloudy water or scaling.

Chlorine (Total/Free)

Our standard chlorine range is 2 to 4 ppm, with a target of around 3 ppm.

Due to Western Australia's climate and heavy bather loads, it is sometimes recommended to aim towards the upper end of this range (around 4 ppm), especially during periods of high use. Free chlorine is the active form responsible for sanitising the water. It is important to maintain adequate chlorine levels at all times to prevent the growth of bacteria and algae. Chlorine levels should be tested regularly, particularly during hot weather and periods of heavy pool use.

Calcium Hardness (Total Hardness)

Our default calcium hardness range is 200 to 400 ppm.

We use an upper limit of 400 ppm because scheme water in Western Australia is often high in calcium and can be difficult to control. In practice, we aim for a target of around 250 ppm where possible. Water that is too soft (low calcium hardness) can be corrosive to pool surfaces and equipment, while water that is too hard (high calcium hardness) can cause scale formation on surfaces and equipment. In WA's hard water environment, managing calcium hardness requires careful monitoring and, in some cases, partial draining and refilling of the pool.

Cyanuric Acid (Stabiliser)

Most equipment manufacturers recommend cyanuric acid (stabiliser) levels between 30 and 50 ppm.

This may vary depending on the type of system you have installed, so always check the recommendations from your pool equipment manufacturer. Cyanuric acid helps protect chlorine from being broken down by UV sunlight, extending its effective life in the pool. Levels that are too low mean chlorine is consumed very quickly, while levels that are too high can reduce the effectiveness of chlorine (a condition known as chlorine lock). If cyanuric acid levels become excessively high, dilution by partial draining and refilling is usually the only remedy.

Other Chemicals and Systems

Other chemicals may be used depending on your equipment, such as copper-based systems, saltwater chlorination and additional specialty products. These will depend on the design of your pool and the specific equipment installed.

Please discuss your particular system with us so we can ensure your water is balanced correctly. If need be, contact your installer, painter or resurfacer to understand what and why you are trying to achieve a certain parameter.

Why Water Balance Matters

Maintaining balanced water chemistry is essential not only for the health and comfort of swimmers, but also for protecting your pool investment. Poorly balanced water can:

Cause premature deterioration of pool surfaces, including paint, gelcoat, fibreglass, pebble, and tiled finishes
Corrode or damage pool equipment, including pumps, filters, chlorinators, and heating systems
Void manufacturer warranties on pool equipment and surfaces if water parameters are outside specified ranges
Create conditions that support the growth of algae and bacteria, resulting in green or unhealthy water
Cause discomfort to swimmers, including eye and skin irritation

A Note on Water Chemistry in Western Australia

Western Australia's scheme water (mains supply water) has specific characteristics that are important to consider when managing your pool:

High Calcium Hardness: Perth's scheme water is notably high in calcium, which means calcium hardness in pools can increase over time through evaporation. This is why our upper target is higher than standard national guidelines.
UV Index: Perth experiences high UV levels year-round, which can rapidly deplete chlorine. This reinforces the importance of maintaining adequate stabiliser (cyanuric acid) levels and testing chlorine frequently during summer.
High Evaporation: WA's hot, dry summers lead to significant water evaporation, which concentrates dissolved minerals including calcium, salts, and cyanuric acid. Regular top-ups and occasional dilution may be required.
Temperature Variation: Water temperature significantly affects how quickly chlorine is consumed and how fast algae can grow. During summer, increased testing and treatment frequency is recommended.

Testing Frequency

We recommend that your pool water is tested regularly throughout the year. As a general guide:

Summer (October to April): Weekly testing of chlorine and pH is recommended, with a full test including alkalinity, calcium hardness, and stabiliser at least monthly.
Winter (May to September): Fortnightly testing of chlorine and pH, with a full test at least every 6 to 8 weeks.
After heavy rainfall: Test and adjust water chemistry promptly, as rainwater can significantly dilute and alter water balance.
After heavy bather loads: Test chlorine levels and top up as needed following pool parties or periods of heavy use.

PLEASE NOTE: If you have recently had your pool resurfaced, or changed your equipment, it is absolutley imperative that you provide this information to us immediately, particularly with the Pool Chemistry Requirements and guidelines required to ensure your warranty remains valid. Maintaining this warranty is ultimately the owner's responsibility, and Poolwise cannot be held liable for any warranty voidance or related issues.

If you have any questions about your pool's water chemistry or our testing services, please don't hesitate to speak with us at your next visit or contact us at info@poolwise.com.au.

Last updated: June 2026