How Do I Know When to Change My ZeroWater Filter? 5 Signs

Culligan with ZeroWater Technology filters are built with 5-stage advanced filtration. This reduces more contaminants than the alternatives, giving you improvements that you can taste, measure, and trust. Like any filter, they need to be replaced to keep performing as intended. The built-in Total Dissolved Solids (TDS) meter is your convenient and reliable guide to know when to change a ZeroWater filter.

When the reading reaches 006 parts per million (ppm), the filter has reached the end of its useful life and should be replaced with a new one. Other cues include changes in taste or odour, a slower flow rate, or visible residue in your jug.

In this guide, we’ll outline five clear signs that it’s time to replace your filter, with practical tips to keep your water consistently pure-tasting. For more advice on caring for your water at home, visit the Culligan blog.

When to Change for Best Results

Replacing your Culligan with ZeroWater Technology filter at the right time means your water stays at its best. The five signs to look out for are:

• The TDS meter shows 006 ppm or higher
• Water develops an unusual taste or smell
• The flow becomes noticeably slower or starts dripping
• You’ve exceeded 150 litres of use
• Visible residue or discolouration appears in the jug

The built-in TDS meter is the most reliable guide, as it gives you measurable proof when it’s time to change. Building the habit of regular checks and timely replacements ensures every pour is as clean and refreshing as the first.

In the UK, tap water is supplied in accordance with strict safety standards under the Water Supply (Water Quality) Regulations 2016. However, local conditions such as pipework and TDS levels can influence how long a filter lasts. For verified details on filtration performance, see our performance & certifications.

1. The TDS Meter Reads 006 or Higher

Every Culligan with ZeroWater Technology jug and dispenser comes with a digital TDS meter. This tool measures the total dissolved solids in your water and gives you instant proof that the filter is working.

When the reading shows 006 ppm or above, the filter is no longer giving you the purest-tasting water. This number is the recognised indicator for replacement, and it provides an objective way to stay on top of filter changes. A higher TDS reading indicates a higher concentration of dissolved solids in your water. Essentially, this means the filter is no longer effectively removing contaminants.

For guidance on how the technology works and why the TDS meter is unique to Culligan with ZeroWater Technology, see our technology page.

2. Your Water Starts Tasting or Smelling Off

Another clear sign your filter is ready to be replaced is a noticeable change in taste or smell. This occurs when the ion exchange resin inside the filter becomes depleted. Once at this stage, it can no longer effectively remove dissolved solids.

The change is harmless at first, but it tells you the filter has reached the end of its useful life. Relying on taste or odour alone isn’t ideal, which is why the built-in TDS meter should always be your first check. Still, if your water doesn’t taste as crisp as usual, it’s time to prepare a replacement.

To make sure you always have one ready, place an order for a Culligan with ZeroWater Technology Filter or Classic ZeroWater Filter today. Keeping spares at home ensures you never have to go without clean, refreshing water.

3. The Flow Slows Down or Starts Dripping

Culligan with ZeroWater Technology filters are gravity-fed. Due to this, water will already take a little time to pass through the 5-stage system. If you notice the flow is much slower than usual or begins to drip, it’s a sign the filter has become clogged with dissolved solids.

A slow flow doesn’t reduce water quality, but it does mean the filter is nearing the end of its capacity. Once contaminants have filled the filtration media, water struggles to pass through efficiently. At this stage, replacing the filter ensures you maintain both performance and convenience.

To keep your jug or dispenser working smoothly, see our manuals & tutorials for guidance on maintenance and cleaning. A well-maintained jug will help your filter perform as expected.

4. You’ve Reached the Filter’s Expected Lifespan

Every filter has a limited lifespan, which depends on both the quality of your water and the frequency of use. For most UK households, a Culligan with ZeroWater Technology filter lasts between 95 and 150 litres before it needs replacing. Homes with higher TDS levels may find their filter reaches capacity sooner.

Tracking litres at home can be tricky, which is why the TDS meter is your most reliable indicator. Still, keeping lifespan in mind helps you plan ahead and avoid running out unexpectedly. Many households find it helpful to build a routine, such as changing filters every one to two months, depending on usage.

To make this easier, consider our subscription offers. They provide better value and ensure you always have a replacement filter ready when your current one reaches the end of its life.

5. Visible Build-Up or Discolouration in the Jug or Filter

A filter that’s been in use for too long can sometimes leave visible clues. Residue, staining, or cloudy water inside the jug are signs that the filter is past its best. This doesn’t mean your water is unsafe. However, it does suggest that the filter media is full and no longer delivering the best taste.

Regular cleaning of your jug or dispenser helps prevent this build-up, but once you see visible changes, it’s time to replace the filter. This keeps your water clear, crisp, and enjoyable to drink.

For step-by-step care advice, visit our support centre. Keeping your jug clean and replacing filters promptly helps maintain both performance and peace of mind.

Stay Ready with Fresh Filters

Staying on top of filter changes ensures that you never compromise on taste or quality. Culligan with ZeroWater Technology makes it simple, with a built-in TDS meter that tells you exactly when it’s time. By watching for the five key signs, you can be confident that every glass is fresh, clean, and measured to zero.

Cleaner water starts at zero, and with Culligan with ZeroWater Technology, you can trust every glass.

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