One of the hardest parts of learning a new topic is getting your head around all of the technical acronyms. These industry-specific jargon terms can be difficult to pin down, especially if they are a collection of initials like TDS with different meanings in different contexts.
While everyone’s water is slightly different, you are unlikely to have Technical Data Schedules or American internet provider TDS Telecom coming out of your taps. Understanding what TDS in water means, how to measure TDS in water, and why measuring water TDS levels is important can help you make informed decisions about the water you consume and use in your home.
This blog will cut through the confusion and explain everything you need to know about TDS in tap water, including its effects, measurement methods, and why Australian homeowners should care about it.
What is TDS in Water?
TDS stands for Total Dissolved Solids, which refers to the total concentration of dissolved substances in water. These substances can include minerals, salts, metals, and organic matter. TDS is usually measured in parts per million (ppm) or milligrams per litre (mg/L).
While some dissolved solids, such as calcium and magnesium, occur naturally and can benefit your health, others, like lead or nitrates, can pose health risks. Excessive levels of TDS can also affect the taste, smell, and overall quality of your water.
Common Sources of TDS in Tap Water
- Natural Sources: Minerals like calcium, magnesium, and potassium often enter water as it flows through rocks and soil. This is the primary source of high TDS in Australian tap water, as so many of our cities use underground aquifers for their water.
- Municipal Water Treatment: Salts used in water treatment, such as chlorine or fluoride, can contribute to TDS levels.
- Pipe Corrosion: Metals like copper, lead, or iron can leach into water from corroding pipes.
- Agricultural Runoff: Nitrates and phosphates from fertilisers may find their way into water supplies.
- Industrial Pollution: Factories and wastewater can introduce harmful dissolved chemicals and heavy metals into water sources.
Why Measure Water TDS Levels?
Your water’s TDS levels are an important part of your overall water quality. Measuring and understanding TDS levels helps you understand what is coming out of your taps and make more informed decisions about appliances and filters.
Measuring TDS can help you stay on top of several factors, including:
1. Health and Safety
High TDS levels can indicate the presence of harmful contaminants, such as heavy metals, pesticides, or industrial pollutants. Measuring TDS helps identify whether additional filtration or treatment is needed to make your water safe for consumption.
2. Taste and Odour
Excessive TDS can negatively affect the taste and smell of your tap water. For example, high concentrations of sodium may make water taste salty, while elevated iron levels may give it a metallic taste.
3. Appliance Longevity
Water with high TDS (often referred to as “hard water”) can lead to scale build-up in household appliances such as kettles, dishwashers, and washing machines. This can reduce efficiency and damage glass or metal components, leading to costly repairs or replacements over time.
Limescale also builds up around taps and shower screens, creating frustrating stains and leading to permanent damage if not dealt with quickly.
4. Gardening and Aquariums
For avid gardeners or aquarium enthusiasts, TDS levels can impact plant health and aquatic life. Measuring TDS lets you make sure you are providing the right water conditions.
How to Measure TDS in Water
Now that we have discussed the importance of TDS, let’s explore how to measure TDS in water.
1. Using a TDS Meter
A TDS meter is a simple and affordable tool that measures the electrical conductivity of water. Since dissolved solids conduct electricity, the meter calculates TDS levels based on conductivity.
Steps to Measure TDS with a Meter:
- Turn on the TDS meter and ensure it’s calibrated (if required).
- Dip the probe into a sample of tap water.
- Wait for the reading to stabilise, usually within seconds.
- Record the value, typically displayed in ppm.
TDS meters are widely available online or in hardware stores and are easy to use for regular monitoring.
2. Laboratory Testing
Simple TDS tests are a great way to see how high or low your water’s dissolved mineral levels are, but they do not tell you anything about the minerals themselves. For a more comprehensive analysis, you can send a water sample to a laboratory. This method provides a detailed breakdown of specific contaminants contributing to TDS, such as heavy metals or nitrates.
3. Home Test Kits
Home test kits often include strips or reagents that change colour based on TDS levels. While these kits are convenient and affordable, they may not be as accurate as a TDS meter or lab testing.
What is an Acceptable TDS Level in Tap Water?
The ideal TDS level for tap water depends on its intended use and individual preferences. While different water utilities and information sources have their own recommended ranges, here is a general guide:
- 0–50 ppm: Highly purified water, such as distilled or reverse osmosis water. Often slightly acidic, may need to have some healthy minerals restored.
- 50–150 ppm: Reasonably soft drinking water, often found in natural springs. May cause minor scale issues.
- 150–300 ppm: Most municipal drinking water supplies fall within this range. These levels are unlikely to impact taste or odour, but you will start seeing elevated limescale and hard water damage.
- 300–500 ppm: Acceptable for drinking, but will often have a gritty or metallic taste. This level is usually found in bore water.
- Above 500 ppm: Poor water quality. A water softener will likely be a necessity to protect your fixtures and appliances, and dedicated filtration may be needed to make sure the water is safe to drink.
In Australia, the Australian Drinking Water Guidelines (ADWG) recommend a maximum TDS level of 500 ppm for palatability, though higher levels may be permissible if the water fits within all other safe parameters.
How to Reduce High TDS Levels
If your water’s TDS level is too high, installing a water filtration system that either filters incredibly thoroughly or has a built-in softener can make a significant difference. Useful types of TDS filters include:
1. Reverse Osmosis (RO) Systems
Reverse Osmosis systems are highly effective at reducing TDS by forcing water through a semi-permeable membrane that removes dissolved solids, including salts, heavy metals, and chemicals. This purification is so thorough that many RO systems (like those from Complete Home Filtration) come with a built-in remineraliser to restore trace amounts of healthy minerals.
2. KDF-55 Heavy Metal Filters
KDF (Kinetic Degradation Fluxion) filters are a specialised filtration medium that is particularly effective for taking heavy metals out of your water. While ordinary carbon filters can struggle to capture dissolved particles and often have no impact on TDS levels, KDF-55 filters can target the more harmful dissolved metals in your water.
3. Ion Exchange Resins
Ion exchange filters are often incorporated into larger filters, like our whole home filter systems.The resin is specifically designed to reduce hard water damage, one of the most common consequences of high TDS levels. It absorbs limescale-causing particles like calcium and magnesium, replacing them with trace amounts of harmless minerals like sodium. While these resin cartridges do not significantly reduce TDS levels (they just replace one dissolved mineral with another), they are highly effective for reducing the harmful and frustrating effects of high TDS in water.
Understanding TDS
“Total Dissolved Solids” is a critical measure of water quality that reflects the concentration of dissolved particles in your tap water. Measuring TDS not only helps you assess the safety and taste of your water but also ensures the longevity of your appliances and the efficiency of your filtration systems.
Whether you’re curious about how to measure TDS in water or looking for ways to lower it, taking action to monitor and improve your water quality is a step toward a healthier, more sustainable home.
For tailored water filtration solutions designed to reduce TDS and enhance the quality of your water, contact Complete Home Filtration today. Experience the difference clean water can make – just send us a message below or call 1300 693 458 🙂
