kichen counter showcasing undersink filter

Under Sink Water Filters: What You Need to Know

Clean, safe drinking water is not just a commodity; it's a necessity of life. From maintaining our bodies' physical health to playing a crucial role in our daily routines, water's importance cannot be overstated. However, access to uncontaminated drinking water has become an increasing concern worldwide, which is where under sink water filters come into play. Installed beneath your kitchen sink, they are compact yet highly effective units that cleanse your water from various contaminants, providing you with a continuous supply of clean, fresh water directly from your tap.

What Are Under Sink Water Filters?

Under sink water filters, as the name suggests, are water filtration systems installed under the sink, connected directly to the water supply line. These devices are designed to filter the water coming from your mains, removing impurities and potentially harmful substances before the water flows out of your kitchen faucet.

These units are renowned for their space-saving design, ease of use, and high-performance levels. Unlike countertop filters or whole-house filters, under sink filters are discreet and conveniently located out of sight, leaving your countertop clutter-free. They also offer the benefit of filtering water at the point of use, ensuring the water you use for drinking and cooking is as fresh and clean as possible.

Under-sink reverse osmosis water filter system installed neatly in a kitchen
Photo by Bluewater Sweden on Unsplash

Types of Under Sink Water Filters

The market offers various types of under sink water filters, each designed to address different needs and preferences. Here's a breakdown of the main types:

Simple Under Sink Filters

These are straightforward filters that connect to your water supply line and filter the water before it reaches your faucet. These are usually the most affordable and easiest to install but may not filter as many contaminants as other types.

Conventional Under Sink Filters

A step up from simple filters, conventional under sink filters come with a separate faucet, typically installed next to your main tap. This system ensures that only the water that flows from the dedicated faucet is filtered, thereby prolonging the filter's lifespan.

Reverse Osmosis Filters

These are the most advanced under sink water filters. They utilize a process known as reverse osmosis to remove even the smallest contaminants, down to 0.001 microns in size. They offer the most thorough filtration, removing almost all contaminants, including heavy metals, salts, and some bacteria. However, they also strip some beneficial minerals from the water, which some users may not prefer.

Benefits of Using Under Sink Water Filters

The use of under sink water filters provides numerous benefits, starting with providing cleaner, safer drinking water. They eliminate a wide range of harmful contaminants, including lead, chlorine, sediment, and bacteria, that can adversely impact your health.

They're also more convenient and cost-effective than buying bottled water. With an under sink filter, you can have unlimited access to filtered water for a fraction of the cost. Plus, you're reducing your environmental footprint by cutting down on plastic waste.

How Under Sink Water Filters Work

Under sink water filters work by forcing your tap water through a series of filters, each designed to remove specific types of contaminants. The number and type of filtration stages vary between models, but most units have at least a pre-filter for sediment and a carbon filter for chemicals and odors.

In more advanced systems like reverse osmosis filters, the water also passes through a semi-permeable membrane that removes smaller particles like salts and heavy metals. The result is clean, great-tasting water, free of harmful impurities.

Installation Process of Under Sink Water Filters

Installation processes for under sink water filters can differ based on the specific type and model. However, most installations involve similar steps. The filter system must be connected to your cold water supply line under the sink. Then, the system is mounted within the cabinet underneath.

For filters with a dedicated faucet, an additional hole may need to be drilled in your countertop or sink to accommodate this separate fixture. It's important to note that while many people can carry out the installation with basic DIY skills and the right tools, some may find it easier and more convenient to hire a professional, especially for more complex systems.

Water filter technician installing an under sink water filter system
Photo by Image by pressfoto on Freepik

Maintenance of Under Sink Water Filters

Maintaining your under sink water filter is critical to ensure it continues to perform optimally. While these systems are designed for long-term use, they do require regular maintenance, primarily involving filter replacements.

The frequency of filter changes depends on the specific model and the quality of your incoming water. Some filters need to be replaced every six months, while others may last up to a year or more. Usually, manufacturers provide guidelines for filter replacement, but if your water has a high level of contaminants, you might need to replace the filters more often.

What to Consider When Buying an Under Sink Water Filter

When choosing an under sink water filter, several factors need to be taken into account:

Filtration Capacity:

It's essential to know what contaminants the filter can remove. Not all filters can remove all types of contaminants, so you should ensure the filter you choose can eliminate the specific pollutants found in your tap water.

Installation Requirements:

Consider if the installation process is something you can handle yourself, or if you would need to hire a professional. Also, check if your kitchen sink and under-sink area can accommodate the filter system.

Filter Lifespan:

This refers to how long a filter can last before needing a replacement. A longer filter lifespan means less maintenance and potentially lower running costs.

Troubleshooting common issues with under sink water filters
Photo by Timur Shakerzianov on Unsplash

Cost of Under Sink Water Filters

The cost of under sink water filters can vary significantly, depending on their type, features, and brand. Simple under sink filters are generally the most affordable, with prices starting from around $50. Conventional under sink filters typically range between $100 and $200. High-end reverse osmosis systems can cost over $500.

Environmental Impact of Under Sink Water Filters

While under sink water filters can help reduce the number of plastic water bottles used and discarded, they do come with their own environmental considerations. Filter cartridges need to be replaced periodically, and incorrect disposal of these used cartridges can lead to environmental pollution. It's vital to follow the manufacturer's instructions for proper disposal or recycling of used cartridges.

Common Issues with Under Sink Water Filters and How to Troubleshoot Them

Like any system, under sink water filters can sometimes encounter issues. Some of the most common problems include reduced water flow, leaks, or changes in water taste or color. Often, these issues can be fixed by replacing the filter cartridge or checking for and fixing any leaks in the system. Regular maintenance and following the manufacturer's instructions can prevent most of these issues.


Installing an under sink water filter in your home is a worthwhile investment towards maintaining your health and well-being. Not only do these filters provide you with clean, fresh-tasting water, but they also offer convenience and cost savings over the long run. With a variety of types and models available, there is an under sink water filter to suit every home and every need. So why wait? Make the switch today and experience the difference of filtered water.


What contaminants can under sink water filters remove?

Under sink water filters can remove a wide range of contaminants, including lead, chlorine, sediment, bacteria, and more, depending on the specific model.

Can I install an under sink water filter myself?

Yes, many under sink water filters are designed for DIY installation. However, some complex systems, like reverse osmosis filters, may require professional installation.

How often do I need to replace the filter cartridges?

This depends on the specific model and the quality of your tap water. Generally, filter cartridges need to be replaced every 6-12 months.

Are under sink water filters environmentally friendly?

Yes, under sink water filters can be a more environmentally friendly option compared to bottled water as they reduce plastic waste. However, it's essential to dispose of used filter cartridges responsibly.

Which brands of under sink water filters are the best?

Brands like APEC, iSpring, and Aquasana are well-known for their quality under sink water filters. However, the best brand for you will depend on your specific needs, preferences, and budget.

Photo by Bluewater Sweden on Unsplash
Back to blog

Related Articles