Water Filtration in Christchurch: What's Actually in Your Water

Why Christchurch households still filter

• Sediment from ageing galvanised or aged pipework, especially after any council main work nearby
• Taste and odour preference, even without contamination
• Bore water on Selwyn and Waimakariri lifestyle blocks, which can carry iron, manganese, hardness or nitrate
• Reducing scale on tapware and appliances in harder-water pockets
• Extra reassurance for households with babies or immunocompromised family members

Whole-house filtration

A whole-house filter sits on the mains supply, usually just after the toby or where the line enters the house, and treats every tap, the shower, and appliances like the washing machine and dishwasher. It suits homes on bore water or anyone wanting sediment and scale reduction throughout the property.

These typically use a sediment pre-filter followed by a carbon stage, sometimes with a water softener added separately if hardness is the main issue. They need a decent flow rate and enough space for the housing, usually in the garage or a service area near the point of entry.

Under-sink filtration

An under-sink unit treats only the kitchen tap, usually with a dedicated filtered-water spout beside the main mixer. It's a cheaper, simpler option when the goal is better drinking and cooking water rather than treating the whole house.

Reverse osmosis systems go a step further, fitted under-sink with a small storage tank, and remove a wider range of dissolved substances. They're worth considering on bore water with nitrate or mineral issues, but they do produce some wastewater and need periodic membrane replacement.

Bore water in Selwyn and beyond

Private bores on rural Selwyn and Waimakariri properties aren't covered by any council water treatment, so what comes out of the ground is what comes out of the tap. Iron and manganese staining, hardness, and in some areas elevated nitrate levels are common enough that we recommend testing the water before choosing a filtration setup, not just guessing.

Once we know what's actually in the water, we can size a system that targets it rather than fitting an off-the-shelf unit that doesn't address the real issue.

Maintenance you shouldn't skip

• Sediment pre-filters typically need changing every three to six months
• Carbon cartridges lose effectiveness over time even if the water still looks clear
• UV sterilisation units, if fitted for bore water, need the bulb replaced annually
• A neglected filter can become worse than no filter at all if it's not changed on schedule

Getting it installed properly

Whole-house units need to be plumbed in with isolating valves either side and a bypass so the household still has water if the filter needs servicing. We size the system to your household's flow rate and fit it so cartridge changes are quick and don't turn into a two-person job.

Frequently asked questions