Owning

Mangawhai Rainwater: When Should You Change Your Water Filters?

Roof collected rainwater is part of everyday life around Mangawhai. The part that is easy to forget is what happens between the roof and your tap.

By Loren Lopez

Updated 30 September 20264 min read

One of the great things about living in Mangawhai is being able to collect our own rainwater.

There is something pretty satisfying about watching the tanks fill after a decent spell of rain, particularly after a dry summer. For many homes around Mangawhai and Mangawhai Heads, roof collected rainwater is simply part of everyday life.

When the system is set up and maintained properly, it can provide fantastic drinking water. The part that is easy to forget is what happens between the roof and your tap.

What your filter is actually catching

Two used rainwater filter cartridges side by side on gravel, heavily discoloured from sediment in a Mangawhai tank water system — These filters have been doing exactly what they are supposed to do. The important part is making sure they are changed before they stop doing it effectively.

Rainwater may look crystal clear when it comes out of the tap, but before it reaches your tank it has travelled across your roof and through your gutters.

Along the way it can collect dust, pollen, leaves, organic matter, bird droppings and other contaminants. Sediment can also gradually build up inside the tank.

That is why filtration matters. The photo above is a good example of just how much material a filter can quietly remove before the water reaches your taps.

If you want to read more about looking after a household rainwater supply, Taumata Arowai, the water services regulator, publishes guidance for people on domestic self supplied drinking water. No filtration setup can guarantee water is safe or pure, so it pays to understand your own system.

Filters are not fit and forget

Probably the biggest mistake with a rainwater filtration system is installing it and then forgetting about it.

A filter gradually loads up with sediment and debris. Over time water flow can reduce and the filter can become less effective.

A sensible routine for Mangawhai homes is:

Check your filters regularly. A quick visual check each month is easy and lets you see how quickly your particular system is loading up.
Check them after major weather events. Heavy rain and wind can wash a surprising amount of material from the roof into the collection system.
Do not wait for the water to taste strange. If a cartridge is heavily discoloured or your water pressure has dropped, investigate it.
Service the whole system. Gutters, leaf screens, first flush diverters, tanks, pumps, filter housings and UV equipment all play a part.
Follow the manufacturer's replacement schedule. Different cartridges and UV systems have different service intervals, so there is no one replacement period that suits every Mangawhai property.

What type of filtration should you have?

Every property is slightly different, but the common options are:

Sediment filtration

This is generally the first line of defence. It removes dirt and suspended material before the water travels further through the system. Many systems use staged filtration, beginning with a coarser filter and then a finer cartridge.

Carbon filtration

Carbon filtration can help improve taste and odour and remove certain unwanted compounds. It is often used as a second stage after sediment filtration.

UV treatment

For homes using rainwater as their drinking supply, UV treatment is worth understanding. UV is used to disinfect water as it passes through the unit. Good filtration before the UV unit matters because clearer water allows the UV system to work as intended.

UV lamps and sleeves also require maintenance, so check the manufacturer's recommended service intervals.

Reverse osmosis

For homeowners wanting another level of treatment specifically for drinking and cooking water, an under bench reverse osmosis system can also be considered. It is normally installed at the drinking water outlet rather than treating every litre entering the house.

Local knowledge helps

This is one of those areas where local experience is genuinely useful.

Grant from Filters & Fountains understands tank water and filtration systems used around Mangawhai. If you are unsure what your current filters are doing, what micron cartridges you should be running, whether UV treatment is appropriate, or how often your particular setup should be serviced, it is worth getting the system checked rather than guessing.

Filters & Fountains can advise on sediment and carbon filtration, whole house systems, UV treatment, reverse osmosis and replacement cartridges.

One of the perks of living in Mangawhai

There are plenty of things to love about living here, and collecting beautiful Mangawhai rainwater is definitely one of them.

But if that water is going into the kettle, the kids' drink bottles and your morning coffee every day, maintaining the system that gets it there is worth a little attention.

If you are not sure when your filters were last changed, take a look.

You might be surprised by what they have been catching.

Water supply is one of the details buyers ask about here, and you can see how it is described on current Mangawhai listings.