Whole-House vs Under-Sink Water Filter: Which Is Right for Your Home?

Whole-house and under-sink water filters are the two systems most Australian households consider when they decide to do something about their water. Both work brilliantly. They just solve different problems.

The right choice depends on what's wrong with your water, how your household uses it and how much of your home you want the filter to cover. Here's a clear-headed breakdown so you can pick the system that genuinely fits.

The one-line difference

A whole-house filter treats every drop of water entering the home. A drinking water filter sits under your kitchen sink and treats only the water coming out of one dedicated tap. That's the entire distinction, and almost every trade-off below flows from it.

Coverage: where the filtered water reaches

Whole-house systems cover the whole house. That means the shower, the bath, the laundry, the dishwasher, the outside taps and yes, the kitchen too. Every fixture benefits from the same filtered water.

Under-sink systems are tap-specific. You typically end up with a small dedicated tap next to your main mixer that dispenses filtered water for drinking and cooking. The shower, laundry and bathroom taps continue running unfiltered mains water.

If your main complaint is the taste or smell of drinking water, an under-sink filter solves the problem. If chlorine in the shower, dry skin and itchy scalp are what brought you here, a whole-house system is the only solution that touches those issues.

What each system removes

Both systems use activated carbon as the backbone of their filtration, which means both reliably reduce chlorine, chloramines, sediment and most chemical tastes and smells. The differences are in the polishing stages.

• Whole-house systems typically run three stages and are sized for high flow rates. They focus on broad protection across the property.
• Under-sink systems can include a reverse osmosis (RO) stage that removes dissolved solids, heavy metals, fluoride and almost everything else, producing exceptionally pure drinking water.

For households that want the ultra-pure drinking water RO provides plus filtered showers and laundry, the most complete solution is actually both systems working together. Whole-house for the property, RO under the kitchen sink for drinking.

Cost: upfront and ongoing

Under-sink systems are the cheaper starting point. A quality multi-stage under-sink unit costs less to supply and install than a whole-house system, and the replacement cartridges are smaller.

Whole-house systems are a larger investment up front because the equipment is bigger, the cartridges handle far more water and the installation is plumbed into your mains. That said, you can spread the cost across an Interest Free Payment Plan through Humm with $0 upfront, so the gap doesn't have to land in one hit.

Ongoing costs come down to cartridge changes. Both systems need filters replaced every 6 to 12 months. Our Filter Care Plan handles delivery and includes a lifetime warranty on the system, which removes the "will I remember?" question entirely.

Installation: complexity and disruption

Under-sink installs are quick. A trained installer is in and out in about an hour. The system tucks neatly inside the cabinet under your sink with a small dedicated tap on the bench above.

Whole-house installs take longer because the system is plumbed into the incoming mains, usually outdoors near the water meter. Water needs to be temporarily shut off and the unit needs to be mounted, but the actual disruption is short. Most installs are completed in a few hours and water is back on before the team leaves.

Which system suits which household?

Choose a whole-house system if:

• You or someone in the home has sensitive skin, eczema or itchy scalp
• The shower smells chemical or like a swimming pool
• You want filtered water for the kids' baths and laundry as well as drinking
• You're on rainwater or bore water and need broad treatment
• You're building or renovating and it's the obvious time to do it once, properly

Choose an under-sink filter if:

• Your only complaint is the taste or smell of drinking water
• You're renting and need a system that can move with you
• You want bottled-quality drinking water without the bottles
• The rest of the household water is genuinely fine

The honest answer

Most of the customers we install for end up with a whole-house system because they realise the chlorine smell in the shower bothered them more than they thought. Plenty of others get exactly the result they wanted with a well-chosen under-sink filter. There isn't a universal "better" system. There's only the system that's right for your water and your household.

The fastest way to find out which one fits is a quick conversation with a specialist who can match the system to your local water. We service homes right across Australia and the call is free, with no pressure either way.