An under-sink filter treats water at one tap, usually the kitchen. A whole house filter treats water where it enters your home, so every tap, shower, bath and appliance gets filtered water. Choose whole house if chlorine in the shower, scale or sediment bother you; under-sink if you only care about drinking water.
- Under-sink = one tap. Whole house = every outlet.
- Many homes use both: whole house for chlorine and sediment, a kitchen stage for drinking water.
- Whole house systems protect hot water systems and appliances; under-sink can't.
What's the difference?
| Whole house (point of entry) | Under-sink (point of use) | |
|---|---|---|
| Where it's installed | At the meter / water inlet | Under the kitchen sink |
| Water treated | Every tap, shower, bath, appliance | One tap |
| Cost | Higher: treats the whole home; depends on your water and plumbing | Lower: treats one tap |
| Shower chlorine | Reduced | Not reduced |
| Protects appliances | Yes (sediment, optional scale control) | No |
| Best for | Families, hard water, tanks, chlorine smell | Drinking water taste only |
Why does the shower matter?
Hot water releases chlorine as a gas, so it concentrates in shower steam. An under-sink filter does nothing for the bathroom. Whole house carbon reduces chlorine before water reaches any shower. Read more in chlorine in shower water.
Can you have both?
Yes, and it's the most common setup we recommend. The whole house system handles sediment and chlorine everywhere; a kitchen stage handles drinking water. In hard-water cities that kitchen stage is reverse osmosis with minerals added back. That's our Whole Home + Mineral package.
Questions
Is a whole house water filter better than an under-sink filter?
It covers more of the house. An under-sink filter only treats one tap. Which is better depends on whether your concerns are limited to drinking water.
Do I still need a kitchen filter with a whole house system?
Not for chlorine and sediment. A kitchen reverse osmosis stage is worth adding if you want hardness or certified PFAS reduction in your drinking water.
- Australian Drinking Water Guidelines, NHMRC
- Standards Australia: AS 3497:2021 drinking water treatment units
Written by the Whole Home Water team and reviewed against the Australian Drinking Water Guidelines. General information only; your Home Water Check gives advice for your home.
Plumbing and installation details reviewed by a licensed plumber. See our editorial policy.