Under-Sink Water Purifier

An under-sink water purifier is a great option if you are concerned about the quality of your tap water. These filters can reduce a variety of contaminants and improve the taste of your drinking water.


Some filters also help reduce odors in your drinking water. Some even offer alkaline filtration that can add back in minerals that are removed during the filtration process.

1. Effective Filtration

There is a wide range of technology, configurations, sizes and price points for under-sink water filters, according to Rick Andrew. He recommends determining what you want to filter out first before choosing a model. For instance, if you’re concerned about chlorine odors and unpleasant tastes in your tap water, an activated carbon option will help address these issues. If you want a more advanced filtration system, a reverse osmosis unit may be a good choice. These work by forcing water through a semipermeable membrane and can reduce a wider range of contaminants.

Most under sink water filters feature pre-filters and a reverse osmosis membrane that remove the vast majority of common pollutants in your drinking water. Some systems also have additional filtration stages to tackle specific contaminants like pharmaceuticals, herbicides and pesticides.

A few under-sink models take this even further. The iSpring RCC7AK 6-Stage Reverse Osmosis System, for example, uses an alkaline filter to add back in healthy minerals and restore the natural pH balance of your water. This helps you get more out of your filtered water and enjoy it to the fullest. These types of advanced under-sink systems can be a bit more costly than basic models, but they tend to offer better results in terms of taste and health benefits. Regardless of your specific needs, it’s important to choose a filter that is NSF-certified and has been third-party tested.

2. Less Maintenance

In contrast to pitcher-based filters and bottled water, under-sink filter systems connect directly to your home’s water line. This means they can provide you with a constant supply of filtered drinking water without needing to refill or wait for the filter to catch up.

Most under-sink water filters are made from carbon or reverse osmosis, which work in slightly different ways. Carbon filters filter water by absorbing contaminants, while reverse osmosis models use pressure to force incoming tap water through a semipermeable membrane that removes most impurities and volatile organic compounds.

Many of these under-sink water filters are also more comprehensive in their filtration than simple pitcher-based options, and can help address a wide range of issues including hardness, chlorine taste, sediment, rust, and heavy metals. They can even reduce bacteria and improve the overall quality of your well water supply.

When it comes time to change the filter, most under-sink water filtration systems require only a quick and easy process. However, it’s still important to clean your filter housing periodically to prevent mildew and algae growth, which can affect the quality of your water.

Cleaning your filter can be as easy as soaking the filter in warm, soapy water, then using a long-handled brush to scrub and rinse. Be sure to turn off your home’s water supply before beginning any work on your filter, to avoid flooding and leaks.

3. Easy Installation

Unlike pitcher filters, under-sink water purifiers intercept your sink’s cold water supply to dispense filtered water through their own dedicated faucet. Campbell notes that “You’ll need to have a decent amount of space under your sink” but that the process is “relatively easy.”

Typically, an under-sink filter will come with tubing that connects to a copper T-adapter that you can install at the kitchen faucet. You’ll then disconnect the kitchen faucet’s tubing from this adapter and install the system’s tubing in its place. You may need to use a wrench for this step. To prevent water from leaking during installation, you can wrap Teflon tape around the tubing and tap the connection to make sure it’s tight.

Some under-sink water filter systems also come with their own dedicated faucet, but others require you to drill a hole in your countertop or use an existing hole from a soap dispenser. For this reason, it’s important to look at the installation instructions carefully before making a purchase.

The most common under-sink water filter uses a filtration cartridge that’s connected to your kitchen faucet by a copper T-adapter. Flow rates can be slow, though, as the system filters out contaminants like arsenic, chlorine, fluoride, lead, and PFOA/PFOS. This system has a monitor that shows your water’s quality at-a-glance, but you may need to replace the filters more often than other models.

4. Better Taste

Many under sink water filter systems produce great-tasting water, which can help you avoid drinking unhealthy bottled beverages. A basic filter can improve your tap water’s taste and remove chlorine and sediment, while more advanced options can reduce fluoride, pesticides, nitrates, and lead. Some also include a built-in carbon block or reverse osmosis membrane, which can remove virtually all total dissolved solids.

The type of under-sink water filter you choose will largely depend on your own needs and budget. If you’re considering a multi-stage water filter, read reviews carefully to find out how often the filters need to be replaced and what contaminants it can remove. Also consider the amount of space under your sink, as larger systems may not fit comfortably in tight spaces.

One disadvantage of under-sink water filtration is that it doesn’t chill the water like a pitcher filter does. This can be an issue for people who prefer chilled water or use their filtered water to make iced coffee, tea, and other cold drinks.

Overall, an Under-sink water filter is a convenient, cost-effective way to enjoy clean, fresh-tasting tap water at home. If you’re a frequent buyer of bottled water, an under-sink filter may pay for itself within months and reduce the amount of single-use plastic waste in your home. You’ll also feel good knowing you’re avoiding harmful chemicals in your drinking water.