How Does Water Filtration Work?

Water filtration systems remove or reduce contaminants from your water supply before it reaches your tap — but the right system depends on what’s actually in your water and what you’re trying to fix.

Sediment filtration

The most basic stage, a sediment filter physically traps particles — sand, rust flakes, general debris — as water passes through, using a fine mesh or cartridge. This is often the first stage in a multi-stage system.

Carbon filtration

Activated carbon filters absorb chlorine, some organic compounds, and are largely responsible for improving taste and odour. This is the technology behind most household jug filters, scaled up for whole-house or under-counter systems.

Water softening

Hard water (high in calcium and magnesium) is addressed differently — a softener uses an ion-exchange process to replace hardness minerals with sodium ions, reducing scale build-up in pipes, geysers, and appliances.

Reverse osmosis

For the most thorough filtration, typically used for drinking water specifically, reverse osmosis forces water through a semi-permeable membrane that blocks a very high percentage of dissolved contaminants, including things sediment and carbon filters can’t catch.

Whole-house vs point-of-use

A whole-house system treats every tap in the property, useful for hardness or general water quality issues affecting your pipes and appliances. A point-of-use system, usually under the kitchen sink, focuses specifically on drinking and cooking water.

Choosing the right setup

The right combination depends on what’s actually in your water — hardness, sediment, taste, or all three — which is worth having assessed before choosing a system, rather than guessing.