Are Under-Sink Water Filters an Eco-Friendly Choice in Australia?

An under-sink water filter is a more sustainable choice than buying bottled water — but how eco-friendly is it really? Here’s an honest look.

See our full Under Sink Water Filters Guide or browse our under-sink filter range.

The Main Environmental Benefit: Eliminating Bottled Water

A household of 4 buying 8 litres/day of bottled water goes through approximately 2,920 single-use plastic bottles per year. An under-sink filter eliminates this entirely. This is the most significant environmental benefit — by a large margin.

Cartridge Waste: The Main Environmental Trade-Off

Cartridge replacement every 6–12 months generates some plastic waste. To minimise it:

• Replace on schedule — an overdue cartridge is less efficient and wastes the energy used to pump water through a restricted filter
• Check with your local council for hard plastics recycling options for the cartridge housing
• The filter media (carbon, ceramic) can go to general waste; some media can be added to garden soil

Water Efficiency

Standard under-sink carbon filters use all the water that passes through them — no wastewater. RO systems produce some wastewater (typically 3–4 litres per litre of filtered water, though modern systems are improving). If water efficiency is a priority, a standard multi-stage carbon filter is more water-efficient than RO.

Energy Use

Standard under-sink filters use no electricity — they operate on mains water pressure. RO systems also use no electricity (they use water pressure to force water through the membrane). Neither system adds to your electricity bill.

Compared to a Benchtop Water Cooler

A bottle-fed water cooler uses electricity for heating and cooling. An under-sink filter uses none. For pure energy efficiency, an under-sink filter has a slight advantage. See our Water Coolers Guide for a full comparison.

Frequently Asked Questions