Question 1

What is spot free water?

Accepted Answer

Spot free water has had its dissolved minerals and salts removed, leaving it with a TDS (Total Dissolved Solids) reading of zero or near-zero. When this water dries on a surface, there are no mineral deposits left behind — so no spots, streaks, or marks.

Question 2

What causes water spots?

Accepted Answer

Water spots form when water evaporates and leaves behind dissolved minerals. Common culprits in Australian water include calcium carbonates, magnesium, silica, sodium, and other dissolved solids. The higher your water's TDS reading, the more spots it will leave behind.

Question 3

What is TDS?

Accepted Answer

TDS stands for Total Dissolved Solids. It measures the concentration of dissolved minerals and salts in water, expressed in parts per million (ppm). A TDS of 0 ppm means no dissolved solids are present. Australian town water typically reads between 50–1,000 ppm, and even bore water or tank water can be surprisingly high.

Question 4

What TDS level is needed for a spot free result?

Accepted Answer

For most applications — car washing, window cleaning, solar panels, caravans — a TDS of 0–10 ppm will deliver a spot free result. For precision applications like battery top-up or laboratory use, 0 ppm is the target.

Question 5

Can I use tap water for a spot free rinse?

Accepted Answer

No. Tap water contains dissolved minerals that will leave spots as the water dries. Even rainwater can cause spots, as it mixes with dust and contaminants already on the surface.

Question 6

What is a DI water filter?

Accepted Answer

A DI (deionisation) water filter removes dissolved ions — minerals, salts, and metals — from water using ion exchange resin. The result is ultra-pure water with a TDS of zero, which air-dries without leaving any residue.

Question 7

What is mixed bed resin?

Accepted Answer

Mixed bed resin is a blend of two types of ion exchange resin: cation resin (which captures positively charged dissolved minerals like calcium and magnesium) and anion resin (which captures negatively charged ions like bicarbonates and sulphates). Together, they strip your water of virtually all dissolved solids, producing water with a TDS reading of 0 ppm. It's the same principle used in laboratory water purification systems.

Question 8

How does a DI filter connect to my hose?

Accepted Answer

PureRinse systems use standard brass click-on garden hose fittings, so they connect directly to your existing outdoor tap or hose. Run tap water into the filter, and spot free water comes out the other end — no plumbing knowledge required. Note: if you want to permanently plumb the system in, the fittings will need to be changed and a PLV pressure limiting valve (up to 500 kpa) must be installed — consult your plumber.

Question 9

Is DI water the same as distilled water?

Accepted Answer

They are both very pure, low-TDS water, but they are made differently. Distilled water is produced by boiling water and condensing the steam — it's energy-intensive, time-consuming, and expensive at scale. DI water is produced on-demand by passing water through resin. For washing applications, DI water is more practical, more cost-effective, and easier to use at the point of rinse.

Question 10

Is DI water the same as reverse osmosis (RO) water?

Accepted Answer

RO water is lower in TDS than tap water but typically still reads 5–20 ppm — not quite zero. DI water, with fresh resin, achieves 0 ppm. For spot free results, DI is the superior choice. Some professional setups use RO as a pre-treatment stage before DI, which extends the life of the resin.

Question 11

Is this the same as a water softener?

Accepted Answer

No — a water softener typically replaces calcium and magnesium ions with sodium ions to prevent scale buildup in pipes, but doesn't remove all dissolved solids. A DI filter uses mixed bed ion exchange resin to remove essentially all dissolved minerals, bringing TDS to zero. The result is truly pure water that dries without leaving any residue.

Question 12

Do I need a carbon pre-filter?

Accepted Answer

A carbon pre-filter is strongly recommended because chlorine in tap water will damage mixed bed resin over time. The carbon stage removes chlorine, sediment, and other chemicals before the water reaches the resin, extending its life significantly.

Question 13

What is the bypass valve and why does it matter?

Accepted Answer

The built-in bypass valve lets you switch between normal tap water and deionised water without disconnecting any hoses. Use regular water for the wash phase to conserve resin, then flip the valve to DI for the final rinse. It saves resin, saves time, and means you only use pure water when you actually need it — during the rinse that dries on the surface.

Question 14

How does the bypass valve save resin?

Accepted Answer

Without a bypass, every litre of water runs through the resin — even water you're using just to soap up or pre-rinse. The bypass valve lets you divert water around the resin during those stages and only push water through the filter for the final spot free rinse. This can dramatically extend the life of each resin fill.

Question 15

How do I use a spot free rinse system?

Accepted Answer

Wash the surface as normal using your regular method. Then, for the final rinse, flip to DI mode and rinse the entire surface from top to bottom. Turn off the water and walk away — the pure water will air-dry without spots.

Question 16

Can I use this for drinking water?

Accepted Answer

No — DI (deionised) water is not designed for drinking. While it's very pure, the deionisation process removes minerals that your body needs, and water that pure isn't suitable or pleasant for consumption. These systems are designed for washing, cleaning, and industrial applications only.

Question 17

Can I let the surface dry in the sun?

Accepted Answer

It is best to avoid drying in direct, harsh sunlight even with DI water, as the heat can cause streaking before the water fully evaporates. Washing in shade, early morning, or late afternoon gives the best results.

Question 18

Do I need to dry the surface after a DI rinse?

Accepted Answer

No — that is the key benefit. With zero TDS water, there is nothing left to form spots when the water evaporates. You can rinse and walk away.

Question 19

What flow rate should I use?

Accepted Answer

DI resin requires contact time to work effectively. Most systems perform best at 5–8 litres per minute. At higher flow rates, dissolved solids can pass through before the resin captures them, which also wears the resin out faster. A standard garden hose or a small pressure washer on a low setting is ideal.

Question 20

How long should a spot free rinse take?

Accepted Answer

For an average car, the final DI rinse should take less than 2 minutes. You only need a curtain of water to flow over the surface — you don't need to soak the vehicle. If you're using a pressure cleaner for the final rinse, set it to a low flow rate to conserve water usage and extend resin life.

Question 21

How many litres of spot free water will I get?

Accepted Answer

It depends entirely on your local water hardness (input TDS). Soft water areas under 60 ppm will get significantly more litres per fill than hard water areas above 140 ppm. In very hard water areas, use the system sparingly and only for the final spot free rinse to minimise resin change-outs. Keeping your rinse flow below 5 LPM conserves resin far more effectively than running at a high flow rate. The bypass valve ensures you only consume resin during the final rinse, not during the whole wash.

Question 22

How do I know when to replace the resin?

Accepted Answer

Test your filter's output water with a TDS meter regularly. Replace the resin when the output reaches 8–10 ppm, or as soon as spotting starts to appear on surfaces — whichever comes first. At that point the resin is saturated and can no longer capture contaminants effectively. See "How do I test for TDS?" for instructions on using your TDS meter.

Question 23

How do I refill the resin in the tank?

Accepted Answer

Unscrew the top head and remove the head and drop tube together as one piece. Dump the old resin out and rinse the vessel. Add a couple of litres of water to the vessel first, then fill with new resin leaving room for the drop tube and screens. Push the drop tube and head back down through the resin and screw the head down firmly. Flush the new resin for a couple of minutes before use. The PureRinse Resin Filler Funnel (sold separately) makes this process clean and mess-free.

Question 24

How do I extend the life of my resin?

Accepted Answer

Keep your flow rate as low as possible (under 5 LPM is ideal), keep the system out of direct sunlight and away from heat sources, and flush the system for at least 1 minute every few weeks to keep the water inside fresh. Store any unused resin in a sealed, airtight container in a cool place out of direct sun to stop it drying out before use. Using the bypass valve so resin is only consumed during the final rinse is the single biggest factor — see the bypass valve FAQ for more detail.

Question 25

Does water hardness affect how long the resin lasts?

Accepted Answer

Yes — significantly. The harder your water supply, the faster the resin will be exhausted. In soft water areas (under 60 ppm TDS) the resin lasts much longer between change-outs. In hard water areas (above 140 ppm TDS) the resin depletes faster. Mixed bed resin will still work regardless of how high the TDS is — it just needs replacing more often. Always use the bypass valve during the wash phase and keep flow rates low to get the most out of each fill. If your water is particularly harsh, consider a larger resin tank or an RO pre-filter stage to extend resin life.

Question 26

How do I test for TDS?

Accepted Answer

Use a handheld digital TDS meter. Simply dip the probe into the water and read the display. Test both your source water (to understand your starting point) and your filtered output water (to confirm the system is working and monitor when to replace the resin). PureRinse systems include a TDS meter.

Question 27

Does it matter if I am on bore water or tank water?

Accepted Answer

Yes — bore water and tank water can have very high and unpredictable TDS levels. Some bore water in Australia exceeds 1,000 ppm. A DI system handles this effectively, but higher source TDS will reduce resin life. Testing your source water TDS before purchasing is a good idea so you can size the system appropriately.

Question 28

Can I use a DI system for washing caravans and RVs?

Accepted Answer

Yes. Caravans and motorhomes have large painted and composite surface areas that show water spots particularly badly. A DI rinse leaves the exterior streak-free with no wiping required — ideal after a trip or before storage.

Question 29

Can I use it for window cleaning?

Accepted Answer

Absolutely. Window cleaners use DI and pure water systems as standard. Glass cleaned with zero TDS water dries completely clear with no smearing, streaking, or mineral residue. It is especially effective when used with a water-fed pole system.

Question 30

Can I use it to clean solar panels?

Accepted Answer

Yes, and it is one of the best applications. Tap water leaves mineral deposits on panels that reduce light transmission and output over time. DI water cleans panels without leaving residue, maintaining efficiency without the need for chemical cleaners.

Question 31

Can I use it for boats and marine applications?

Accepted Answer

Yes. Salt air and spray mean boats accumulate mineral and salt deposits quickly. A DI final rinse removes these without spotting, and is safe on gelcoat, fibreglass, and painted surfaces.

Question 32

Can I use it to top up batteries?

Accepted Answer

Yes. Deionised water is the correct water for topping up lead acid batteries, including car, golf cart, and forklift batteries. Tap water introduces minerals that cause scale and reduce battery performance. Zero TDS DI water is ideal.

Question 33

Are there other uses for DI water?

Accepted Answer

DI water is also used for steam irons, CPAP machines, fish tanks and reef aquariums, electronics and PCB cleaning, CNC coolant systems, and laboratory or scientific applications where mineral-free water is required.

Question 34

Do you ship Australia-wide?

Accepted Answer

Yes — we ship to all states and territories across Australia. Use the contact form to enquire about shipping rates to your area or for bulk orders.

How a DI Water Filter Works

Connect

Flip to DI

Rinse

What's happening inside the filter

Know when to refill

Refilling takes minutes

Store it right

Frequently Asked Questions