Joybuy Insights

Choosing a water filter: a practical guide to jugs, tap filters and systems

Would you like to filter tap water for a milder taste, less limescale build-up or fewer plastic bottles? Choosing a water filter might seem straightforward. However, there are clear differences between a water filter jug, a tap filter and a reverse osmosis water filter.

Look out for these three common pitfalls:

  • A large capacity doesn’t necessarily mean lots of filtered water. For example, a 2.4-litre jug may hold only 1.4 litres of filtered water.
  • A long lifespan is only useful if the replacement limit is clear. Always check both the number of litres and the maximum recommended usage period.
  • “Pure” doesn’t automatically mean suitable for every water source. Most household filters are designed for cold tap water that is microbiologically safe. They don’t automatically make unknown or non-potable water safe to drink.

Which specifications matter?

1. Filter capacity and replacement time

Compare water filter cartridges based on their stated capacity. According to the product information, some MAXTRA PRO cartridges can filter up to 150 litres or last four weeks, whichever comes first. Another system may specify a usage period of around 35 days.

A household with several coffee drinkers will use considerably more filtered water than a single person. Work out how many litres you’ll need each week in advance. A larger-capacity model, such as a water filter dispenser, may be more practical for families.

Don’t use a cartridge for longer than recommended. A saturated filter may become less effective and, if not maintained properly, could retain or release unwanted substances. Always follow the manufacturer’s instructions.

2. Filter technology

A traditional water filter jug often uses a combination of activated carbon and ion exchange. According to BRITA’s product information, this combination can reduce water hardness, chlorine and certain substances that affect taste and smell. Some cartridges also list metals such as lead and copper. These are claims made in the brand’s product information; the precise results depend on your tap water and how well the filter is maintained.

A limescale filter is particularly useful if you want to reduce limescale build-up in a kettle, coffee machine or tea glass. Check that the cartridge you choose is specifically designed to reduce water hardness.

A reverse osmosis water filter offers more extensive filtration. According to the manufacturer, the Waterdrop system in this selection uses a five-stage process that includes an RO membrane, activated carbon and PP cotton. The manufacturer states that it reduces TDS, fluoride, chlorine and certain heavy metals, among other substances. Always consider these performance claims in relation to the specified model, filter status and water source.

3. Capacity, size and ease of use

A tap water filter should suit your kitchen and daily routine. Look out for:

  • Filtered capacity: check more than just the jug’s total capacity.
  • Dimensions: make sure the jug will fit in your fridge door.
  • Filling: a lid that opens with one hand is handy for everyday use.
  • Maintenance: check whether the parts are dishwasher-safe and which parts are excluded.
  • Filter indicator: a mechanical or electronic reminder makes it less likely that you’ll forget to replace the cartridge.
  • Temperature: the products listed are designed for cold water. Don’t fill a filter jug or tap filter with hot water.

A water purifier that needs to be plugged in also requires space near a socket. Check the clean water tank capacity, the amount of wastewater produced by RO systems and the price of replacement cartridges.

Recommended water filters for different needs

Suitable for: Budget-conscious beginners
Xiaomi Faucet Water Purifier Filter

Xiaomi Faucet Water Purifier Filter

Why it suits this profile: This tap filter is designed to fit most standard taps and, according to the product description, uses activated carbon and PP cotton. It’s a compact way to try filtering tap water without keeping a separate jug in the fridge.

How this product avoids the pitfall

The stated lifespan is up to three months. Check that it’s compatible with your tap before buying, and replace the filter according to the instructions.

Key benefit & features

Compact design, compatibility with standard taps according to the description, and filter material made from activated carbon and PP cotton.

Suitable for: Shoppers looking for premium quality
BRITA Marella Water Filter White 2.4L + 6 Maxtra Pro

BRITA Marella Water Filter White 2.4L + 6 Maxtra Pro

Why it suits this profile: The water filter jug has a total capacity of 2.4 litres, including 1.4 litres of filtered water. The six cartridges included provide enough for several replacements.

How this product avoids the pitfall

According to the product information, the Memo reminder indicates when the cartridge should be replaced, after around four weeks. The actual capacity depends on usage and water hardness.

Key benefit & features

Fridge-friendly size, filling flap and six MAXTRA PRO cartridges included. According to the product information, the jug is dishwasher-safe, except for the lid.

Suitable for: Specific needs & heavy users
Waterdrop WD-A2 Countertop Reverse Osmosis System

Waterdrop WD-A2 Countertop Reverse Osmosis System

Why it suits this profile: This countertop model is designed for people looking for a more extensive system for the kitchen, office or caravan. According to the product description, it offers six temperature settings from 15 to 95 °C.

How this product avoids the pitfall

The filter status is shown on the display, making it easier to see when maintenance is needed than with a system without an indicator. Bear in mind the electricity use, tank cleaning and wastewater.

Key benefit & features

Five-stage RO filtration according to the manufacturer, real-time TDS display, self-cleaning function and a removable 1.1-litre clean water jug.

Looking for more options?

We’ve put together a full, up-to-date list of products that meet these strict selection criteria and the applicable European safety regulations.

Frequently asked questions about water filters

How often should I replace a water filter?

It varies by brand, cartridge and water consumption. Many cartridges have a limit of around four weeks or a set number of litres, such as 150 litres. Always follow whichever limit is reached first. A filter indicator is useful, but it doesn’t replace the instructions on the packaging.

Can I run warm water through a water filter?

Usually not. Water filter jugs, tap filters and many cartridges are designed for cold tap water. Hot water can damage the filter material or plastic parts. For tea and coffee, filter cold water first, then heat it in a suitable appliance.

Is a water filter cheaper than bottled water?

That depends on the purchase price, filter capacity and how much you use. Calculate the cost per litre by dividing the price of a cartridge by its stated capacity in litres. Include any purchase costs for the jug or dispenser too. A water filter can also reduce the number of single-use bottles you buy, but the savings will vary from household to household.