Clean, safe and refreshing water is essential for maintaining good health and well-being. In the United Kingdom, we are lucky to have some of the best tap water in the world, however there are instances where contaminants or impurities may still be present. These impurities can have a significant impact on the taste, odour and appearance of your water.

This is where water filter cartridges play a crucial role – by effectively removing various contaminants and impurities, ensuring that you and your family can enjoy high quality, great tasting water. Today we’ll take a deep dive into the world of water filter cartridges to explore the different types, common sizes and typical applications, to help you get a better understanding of the types of what a filter cartridge is and why you would use one. 

What Is A Filter Cartridge?

Filter cartridges are one of the most common forms of water filter available on the market. The reason for this is their convenience, low cost and popularity, with most options being manufactured to industry standard sizes.

A filter cartridge has a tubular design (similar to a paint roller) which allows it to fit inside of a filter housing. The housing encapsulates the cartridge and allows water to be passed through it on demand. For example, our range of Water Filter Cartridges are suitable for all types of different filter housings – just match up the correct size.

Other Common Names For Filter Cartridges:

• Drop In Filter Cartridges
• Candle Filters
• Filter Inserts

Different Types Of Water Filter Cartridges

Filter cartridges come in all shapes, sizes and materials. It is the size of the filter cartridge that usually determines the ‘flow rate’ or the amount of water that can pass through the filter over a given time, whilst the material of the cartridge determines the type and efficiency of filtration.

As experts in water treatment, we have curated a comprehensive selection of water filter cartridges – each option tackling different applications to give you full flexibility over your water quality. Below is a summary of some of the most common types available.

Sediment Filters

Sediment filters typically employ mechanical filtration, which is where small pores (often of a given ‘micron’ size) allow water to pass through, whilst larger particles are trapped and retained in the filter cartridge. The principle of mechanical filtration is simple – it is exactly the same as when you drain pasta in a colander, the pasta is retained in the ‘filter’ and the water is allowed to pass through.

Carbon Filters

Carbon filter cartridges are by far the most popular for drinking water applications because they drastically improve the taste and smell of your water. Activated carbon contains millions of tiny pores which adsorb and remove lots of contaminants including chlorine, pesticides, herbicides, solvents and even some PFAS from your water. Carbon cartridges are so effective at removing chlorine, they are often used as part of multi-stage filtration processes. For example as a pre-filter to a reverse osmosis system.

Fluoride Filters

As the name suggests, fluoride filter cartridges are designed to target fluoride and remove it from your water. The presence of fluoride in drinking water is a concern for many customers, who cite its impact on general well-being and mental health. These cartridges use a fluoride-selective resin, which specifically targets fluoride and removes it from your water.

Limescale Filters

Limescale filters offer a targeted solution to tackle limescale build up. Those who live in hard water areas are probably aware of the damage that it can cause, such as clogged shower heads and poor boiler lifespan. Luckily there are a range of filter cartridges available to help alleviate the problems caused by limescale, such as TAC, polyphosphate and softening resin filters which all work in differing ways.

Media Filters

Media filters, sometimes known as ‘resin filters’ contain different media types such as softening resin, de-ionising resin, or pH correction media to tackle a number of common water treatment conundrums. They typically consist of an empty cartridge ‘shell’ that is filled with the chosen media. One example of their use is for small batch DI water production, to produce pure water on demand for lab or aquatics applications.

Common Filter Cartridge Sizes

Water filter cartridges come in various sizes to accommodate different filtration systems and flow rates. Some of the most common industry standard sizes include:

1. Standard 10-inch Cartridges: These cartridges are widely used in countertop and under-sink water filtration systems. A standard 10” filter cartridge is typically 9 ¾ – 10” in length and 2.5” in diameter, with a 1” hole through the centre.
   
   
2. Standard 20-inch Cartridges: These cartridges are commonly used in whole house, borehole and light commercial filtration systems. A standard 20” filter cartridge is typically 20” in length and 2.5” in diameter, with a 1” hole through the centre.
   
   
3. Big Blue 10-inch Cartridges (BB): Larger than the standard size, these cartridges are often used in whole-house filtration systems, borehole, commercial and industrial filtration systems. Their larger diameter allows for a higher flow rate and extended filter life. A big blue 10” cartridge is typically 9 ¾” – 10” in length and 4 ¼ -4 ½” in diameter, with a 1” hole through the centre.
   
   
4. Big Blue 20-inch Cartridges (BB): Again larger in diameter than the standard size, these cartridges are often used in high flow rate applications, such as in agriculture, manufacturing and food and beverage applications. Their larger diameter allows for a higher flow rate and extended filter life. A big blue 10” cartridge is typically 9 ¾” – 10” in length and 4 ¼ -4 ½” in diameter, with a 1” hole through the centre.
   
   
5. Inline Cartridges: Designed for compact spaces and low flow rates, inline cartridges generally do not require a filter housing, which is why they are sometimes referred to as ‘encapsulated’ filters. They usually feature quick and easy push-fit connections and sit inline with the pipework, making them popular for point-of-use systems like fridges, coffee machines and water coolers.

Common Filter Cartridge Applications

Drinking Water Filtration

Water filter cartridges are most commonly used to improve the taste and quality of drinking water – making it more palatable for daily consumption. Whether you’re looking to remove chlorine, odours, or fine particles from your water, there are a number of different cartridges suitable for your needs.

Cooking & Food Preparation

Using filtered water in cooking and food preparation can enhance the flavour and appearance of dishes. It also ensures that potential contaminants are eliminated from your ingredients. Limescale filters are often used in catering applications, to protect expensive equipment like coffee machines and steam ovens from limescale damage.

Household Appliances

Water filter cartridges are often used to extend the lifespan of appliances like coffee machines, kettles, and washing machines by preventing the buildup of limescale and sediment. Left un-managed excess limescale build up significantly reduces appliance lifespan and impacts the taste of your favourite hot beverages.

Gardening & Plant Care

Filtered water can be beneficial for your plants, as it eliminates chemicals and contaminants like chlorine that could hinder their growth. Some filter cartridges are designed specifically for horticultural use.

Fishkeeping & Aquatics

Whether fresh water, tropical or marine the water quality for fishkeeping is paramount. For fresh water and tropical tanks it is important to remove sediment, chlorine and chloramines from the water. Whereas in marine applications pure water with no dissolved solids is required as a base before adding salt to replicate the specific gravity of marine water.

Caravans, Motorhomes & Boats

When on the road or at sea the quality of the water you take onboard can vary greatly from location to location. With filtration typically employed to remove sediment, chemicals and potentially harmful bacteria from the water.

Choosing The Right Filter Housing

You may have heard the term ‘Filter Housing’ being thrown around a lot in this post – and that’s for good reason! In most instances you can’t use a filter cartridge without a housing, so it makes sense to cover them too. Luckily, filter housings are incredibly straight forward, with just a few things to consider.

• Housing Size – The size of housing should be matched against your filter cartridge. Considerations should be made towards flow rate, temperature and pressure requirements, to make sure the housing and cartridge combination is suitable for what you plan to use it for.
  
  
• Port Sizes – Port sizes or thread sizes should be matched up to your requirements. They typically feature BSP or NPT threads, with the most common sizes including 1”, ¾” or ½” – all sizes that can easily be adapted to standard UK pipework sizes such as 15mm and 22mm.
  
  
• Housing Colour – Filter housings come in many different colours, with opaque blue and clear being the most common. When used outside with the potential for UV light to penetrate the filter housing, you should usually opt for an opaque finish to prevent biological growth inside the housing. Clear housings are preferred for most people as they allow for easy visual checks of both water clarity and cartridge lifespan.

Final Thoughts…

To summarise, water filter cartridges are essential components of water treatment systems, allowing for cleaner, safer, and better-tasting water. From sediment filters to activated carbon filters, each type of cartridge serves a specific purpose in addressing various water quality concerns. By understanding the common cartridge sizes and applications, you can make informed decisions about the best filtration solution for your needs. Whether you’re seeking to improve your drinking water or protect your appliances, water filter cartridges play a vital role in ensuring the health and comfort of your home and the people in it.

Browse our range of Water Filter Cartridges today and start taking control of your water. If you need help specifying a system that meets your requirements, feel free to give us a call on 01622 933 853 or by contacting us through live chat or email.