When point-of-use under-sink filters are enough, when a whole-house system makes sense, and what changes if you are on bore or rainwater instead of mains supply.
Water filtration has gone from a niche extra to a fairly standard ask in Kapiti kitchens and bathrooms. Most of the time a single under-sink filter on the kitchen tap is all a household needs. Sometimes a whole-house system makes more sense. The right answer depends on what is coming in at the boundary.
Point-of-use filters
A standard 3-stage under-sink filter (sediment, carbon block, polishing) plumbs onto the cold feed at the kitchen sink. It improves the taste of drinking water, removes chlorine, and traps any sediment that makes it past the mains. Cartridges last 6 to 12 months and replace in minutes. For most town-supply households this is enough.
When whole-house makes sense
- You are on bore water or rainwater and want consistent quality at every tap.
- Sediment is staining fixtures, building up in toilet cisterns or shortening the life of appliances.
- You are sensitive to chlorine in shower water or laundry.
- You have a softener installed and want filtered water at every fixture.
A whole-house system installs on the mains feed where it enters the house, before it splits to internal fixtures. It typically combines a coarse sediment filter, a fine carbon stage, and (for bore or rainwater) UV sterilisation. Cartridges and lamps are serviced annually.
Bore and rainwater systems
Bore and rainwater installations on the Kapiti Coast have an extra consideration — biological contamination. Town mains supplies are chlorinated; bore and rainwater are not. A whole-house system with UV sterilisation is the standard treatment, and the UV lamp is the part that needs the most attention (annual replacement). Tony installs and services bore/rainwater systems across rural Otaki, Te Horo and surrounds.
What it actually costs
A 3-stage under-sink filter installed typically lands at $400 to $700 + GST. A whole-house mains-supply system runs $1,500 to $3,000 + GST. A bore or rainwater system with UV is $2,500 to $4,500 + GST depending on flow rate and tank pressure setup. Annual servicing is straightforward and predictable.
Free assessment — Tony can test water on-site and recommend the smallest system that solves the actual problem, rather than the biggest catalogue option.