How to use your Spot Free Rinse system. Let's get you set up.
Using a spot free rinse system is simple: wash as normal with tap water, switch to your Spot Free Rinse tank for the final rinse, then let everything air dry — no towels, no spots. The tank produces demineralised (deionised — also spelled deionized) water, the same spot-free water sold in bottles, straight from your tap. Watch the video, then work through each section at your own pace.
Get the most out of your resin
Your resin is the heart of the tank. A few habits will make it last a lot longer.
Final rinse only. Wash with regular tap water, then use the tank for the last rinse only. Running the whole wash through it exhausts the resin many times faster.
Shake it regularly. Every few washes, lift the tank and shake it side to side and upside down. This stops water channelling through the resin. TDS may rise for about 30 seconds, then settle back to 0.
Keep it cool. Heat damages resin, so store the tank in your garage out of direct sunlight. Using it in the sun is fine, flowing water keeps the resin cool.
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Store it sealed. Leave the bypass head on "bypass" between washes so water stays in and air stays out. Air exposure slowly degrades resin.
Keep water inside when shaking. The resin needs water to move freely. Bypass head: switch to "bypass" first. No bypass head: connect the supplied 2m hose to both ports to seal the water in, then shake.
Use a pressure washer made for car washing. Lower flow than a full house tap means more contact time with the resin, better purification and longer resin life.
Know your water. Resin life depends on dissolved minerals. Hard water areas and frequent, high volume use exhaust it faster. Once TDS creeps above 10 ppm, it is time to replace the resin.
Essential information
Three quick panels to help you connect the tank, understand the bypass, and use purified water the right way.
What's in the box
Quick check
- Your Spot Free Rinse deionised water tank — pre-filled with premium ion exchange resin in the size you selected
- Male garden hose connectors
- An external bypass valve
- Approximately 2 metres of hose
- A TDS meter
- Instruction card with QR code
Connecting the tank
Setup in a few steps
- Connect your bypass system so the unit is used for the final rinse only. This system is designed for purified water at the end of the wash, not for the entire wash process.
- Connect your incoming tap water to the IN side of the system.
- Connect your outgoing hose to the OUT side of the system.
- Water flows down through the tank, passes through the resin, then travels back up the centre tube and exits as purified water.
- Use the shorter hose at the tap and run the longer hose out to the car — or run the longer hose to the tank and keep the tank closer to the car or pressure washer.
- Keeping the tank closer to the car can help preserve resin life slightly, as it leaves less purified water sitting in a long hose once you've finished.
How to use it properly
Final rinse or full rinse
- Wash your car as normal, starting from the top and working in sections.
- If washing in the sun, rinse each section before the soap has a chance to dry.
- If washing in the shade, you can do the full wash with tap water and switch to purified water right at the end for the final rinse.
- The goal is to rinse tap water off the surface before it dries.
- Using purified water only for the final rinse helps preserve resin life.
More information
Learn more about TDS testing, bypass use, troubleshooting, and how to get the most life from your resin.
Using the TDS meter
Check your water
The TDS meter measures total dissolved solids, which tells you how many minerals are in the water.
- Turn the meter on.
- Remove the bottom cap.
- Fill the cap with water.
- Place the meter into the cap to take a reading.
- Your tap water may read anywhere from around 30 to 500 ppm depending on your area.
- Water coming out of the tank should read 0 ppm when the resin is fresh.
- As the resin is used up, the reading will start to rise.
How the bypass works
Save resin
The bypass lets you do most of the wash with normal tap water, then switch to purified water only when you need it.
- Bypass mode: water bypasses the tank and isn't purified — use for the main wash, not for the rinse.
- Filter mode: water flows through the tank and comes out purified — use this for the final rinse for a spot-free finish.
- This helps preserve resin life and avoids wasting purified water.
- When switching from bypass to filter, flush out any tap water left in the hose before starting your final rinse.
- Especially useful in hard water areas such as WA, SA, or some regional areas.
If you still see marks after drying
Troubleshooting
If you notice anything left behind after the rinse, a few things may be causing it:
- The resin may be exhausted and need replacing.
- Your TDS reading may no longer be 0.
- Dust in the air may be settling on water droplets as they dry.
- There may already be existing water spots embedded in the paint and glass — use polish or water-spot remover and wash again.
- Your detergent may contain waxes or sealants that leave residue behind.
After-use care and storage
Make it last longer
As the tank is used, the resin at the top gets depleted first.
- If your TDS starts reading around 1 ppm, you may be able to extend resin life slightly by redistributing the resin.
- Leave water in the tank, plug the end so water stays inside, then lift and gently shake the tank.
- This is more useful on smaller tanks than very large ones.
- Store the tank out of direct sunlight, ideally in a garage or shaded area.
- Heat can degrade the resin faster.
- Keep the hose connected on both ends during storage to reduce oxygen exposure.
Helpful final tips
Best results
- Work top to bottom.
- Don't let soap or tap water dry on the surface.
- If washing in full sun, work in smaller sections.
- If washing in shade, use tap water for the wash and purified water for the final rinse.
- Check the output water with your TDS meter when needed.
- If you're unsure about your setup, call or message for help — there are a few different ways it can be done.
Spot free rinse questions
The questions we get asked most about deionised water and spot-free rinsing.
What is deionised water?
Deionised (DI) water is water that has had its dissolved minerals removed by ion exchange resin. Because there's nothing dissolved in it, it evaporates without leaving spots, streaks or residue — which is what makes a deionised water system the secret to a spot-free finish on cars, windows, caravans and solar panels.
Is demineralised water the same as deionised?
For rinsing purposes, yes. The demineralised water sold in bottles at hardware and auto stores is water with its minerals removed — the same thing your tank produces. The difference is scale and cost: instead of buying bottles, a portable spot free rinse system makes demineralised water for car washing straight from your garden tap, hundreds of litres at a time.
What TDS reading means the water is spot free?
0 ppm is the spot-free benchmark — fresh resin delivers it consistently. As the resin wears, readings creep up; below about 10 ppm you'll generally still get a clean result, but once your output passes 10 ppm it's time to replace the resin. Test with the TDS meter included with every tank.
Can I use bore or tank water?
Yes — the system purifies whatever you feed it, but the input TDS decides how long your resin lasts. Rainwater tank water is usually very low TDS, so resin lasts longer than on town water. Bore water is often very high TDS (especially in WA and regional areas), so resin exhausts faster. Test your source with the TDS meter so you know what to expect.
Is deionised water safe for car paint and ceramic coatings?
Completely. Deionised water contains no minerals or chemicals, so it's safe on paint, clear coat, ceramic coatings, PPF, wax and sealants — it won't strip or degrade any protection. It's actually gentler than tap water, and because nothing needs towel drying, there's less contact with your paint and less chance of swirl marks.
Can I wash the car in direct sunlight with spot free water?
Yes — that's one of the biggest advantages of spot free rinse at home. Because the final rinse water is mineral-free, it dries in the sun without leaving spots. Just rinse the soapy water off each section before it dries, then let the purified water air dry on its own — no racing the clock, no towels.
