Understanding Water Filter Micron Ratings: What Level of Filtration Do You Need?

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You can’t see them, but what slips through your filter tells you everything about how effective it really is. The truth is, not all water filters are created equal, and micron ratings are one of the most important features. Knowing and understanding what you need helps in choosing the right filter for your water supply needs and lifestyle.

At Water Filters Australia, we’ve been servicing the nation with high-quality, long-lasting, fully certified water filter products since 1999. Our inline filtration systems rely on tried and tested filters with appropriate micron ratings for local water conditions.

When we measure most things, it’s not usually in the millionths of anything. In water filtration, that’s where we’re at. A micron is a unit of measurement that is equal to one micrometre, or one millionth of a metre. For some perspective, a single human hair is about 70 microns wide. But considering that some of the most problematic things in drinking water are microscopic, it makes sense that filtration operates at such tiny fractions.

So what does a micron rating actually tell you? Simply put, it’s about how small the particles are that a filter can catch. A 1-micron filter, for example, will stop anything larger than one micron, which includes things like rust, dirt and sediment, and in some cases certain parasites.

Finer doesn’t always mean better. A lower micron number gives tighter filtration, which means water moves through the filter more slowly. That can reduce pressure if the filter isn’t designed well. WFA filters are engineered to balance effective filtration with strong flow, which is why we use a micron rating that captures what matters without compromising performance.

Different micron ratings are suited to different types of water concerns. Here’s a quick breakdown of what each level targets.

When you see a micron rating on a water filter, it’s usually either nominal or absolute, and this might seem like a small detail, but it matters. Here’s what they mean:

• A nominal rating is for filters designed to capture most particles of a given size. “Most” is generally around 85%, though this depends on the material and flow conditions. Nominal ratings are a more general approach and are well-suited to standard residential use.
• An absolute rating indicates the filter has been tested to block 99.9% of particles at that size. These filters are frequently used in medical and industrial settings where a higher level of precision is required. At WFA, we do have options available with an absolute micron rating, offering this standard of protection in systems designed for everyday residential use.

For most families in cities and towns across Australia, a 1 micron water filter provides a strong level of protection without affecting the flow of water preferred for daily use. It’s fine enough to catch sediment, rust and some protozoa cysts, while still allowing good pressure. That balance is particularly important when enjoying the convenience of an inline water filter installed in your kitchen or bathroom, both busy areas in modern homes.

If your water supply isn’t visibly dirty or unusually high in sediment, choosing a filter finer than 1 micron can actually slow things down significantly for little benefit. That’s why our inline filter systems are built around that benchmark. It’s a practical threshold for pure drinking water as it removes the nasties while remaining extremely efficient.

And there’s a lot more to filtration than just micron ratings. The way a filter is built, what it’s made from, and the type of media inside all influence how well it performs. For example, filters that contain activated carbon, like those at WFA, can reduce chemical compounds such as chlorine, which micron size alone doesn’t address.

Micron ratings might sound like complex scientific jargon, but understanding them gives context to what water filters are really doing behind the scenes. Now you know how to interpret them, you’re better equipped to read labels, compare products and appreciate the process behind every refreshing glass of filtered water.

At Water Filters Australia, our inline water filters are designed for Australian homes, with clear specs you can review for reassurance you’ll have superior filtration at your fingertips. They are manufactured in the United States to the highest quality standards and are available online from our national distribution centre. We only supply independently Watermark Certified systems, and we stock a complete inventory of certified replacement cartridges with 100% Australian-based customer support.

Shop online today or contact our team for personalised advice on the best system for your home or caravan.