Under-Sink vs. Whole-Home Filtration: What’s Right for You?

Aug 15 , 2023

Under-Sink vs. Whole-Home Filtration: What’s Right for You?

Choosing the right water filtration system is essential for ensuring that your water is clean and safe for yourself and every member of your family.

Two popular options are under-sink and whole-home filtration systems. In this blog, we’ll explore each system’s pros and cons to help you make an informed decision based on your requirements.

Important Note: Before going any further, test your water supply to learn which contaminants are in your water. After you test your water, you’ll know the type of filter you need (reverse osmosis, ion exchange or carbon filtration) for whichever filtration system you choose.

What Type of Filter Do I Need?

Depending on how much you want to filter your water, and what contaminants you want to eliminate, there’s three different types of filters to choose from:

  • Reverse Osmosis: Simply pushes tap water through a semipermeable membrane to dissolve inorganic solids for great-tasting water. Features reasonable pricing, no necessary user involvement and simple kitchen tap installation. Recommended if your water quality has a wide range of contaminants or bacteria.
  • Ion Exchange: Water travels over a resin (typically beads) that replaces unwanted ions with more desirable ions to soften and purify the water. Typically, this refers to replacing hard water minerals (calcium, magnesium) with sodium ions.
  • Carbon Filtration: Uses efficient carbon filters to improve water taste while removing contaminants and impurities including chlorine, odors, sediment and other VOCs (volatile organic compounds); however, carbon will not remove minerals and salts. Filters need to be changed periodically. King Water Filtration systems operate through carbon filtration.

Now that we’ve profiled the different types of filters, let’s take a look at the two types offered by King Water: our under-sink and whole-home models.

Under-Sink Filtration Systems

Manufacturers specifically design under-sink filtration systems to provide cleaner, better-tasting drinking and cooking water. They are a practical choice for anyone who is concerned about contaminants and are typically installed in the kitchen.


  • Effective and Convenient: Under-sink systems are more effective at removing lead, chlorine, and other harmful contaminants than water filter pitchers and faucet arm filters, and they’re way more convenient and out of the way.
  • Affordability and Easy Installation: While more expensive than water filter pitchers and faucet arm filters, compared to whole-home filtration systems, under-sink filters can be more affordable. They also install easily without requiring major modifications to your sink plumbing, and they save valuable space in your kitchen by keeping your countertops clutter-free.


  • Limited Protection: While these systems are excellent for filtering drinking water, they do not provide comprehensive protection against contaminants in other areas of your home and do not address the issue of hard water scale, which can lead to mineral buildup in other household fixtures and in your plumbing.
  • Impact on Water Pressure: Some under-sink systems may slightly reduce water pressure at the spout due to the filtration process.

Whole-Home Filtration Systems

Whole-home filtration systems offer a more comprehensive approach to water purification. These systems filter water at its point of entry into the home, providing clean and safe water for all household uses.


  • Comprehensive Filtration: Whole-home systems offer a wide range of filtration, effectively removing sediment, VOCs, pesticides, heavy metals and other contaminants throughout the entire house.
  • Minimal Impact on Water Pressure: Unlike under-sink filters, whole-home systems typically have a negligible effect on water pressure throughout the house.




  • Price: Larger and more advanced whole-home filtration systems cost more than under-sink options.
  • Size and Installation: The size and complexity of whole-home systems may require professional help for installation, making them less suitable for rental properties.

The King Water Difference

King Water Filtration systems are not water softeners but rather comprehensive water filters that also condition the water to prevent hard water scale without the need for salt. Our systems do not remove the healthy minerals from the water – they instead change the chemical structure of the minerals to stop them from forming scale inside your pipes and on your fixtures. All King Water systems adhere to NSF/ANSI 42 and 61 standards to provide clean and safe drinking water, and there is no need to use salt, replace filters or worry about any kind of maintenance.

So, the choice between an under-sink system and a whole-home system ultimately depends on your specific needs and circumstances. Filtered water for basic drinking and cooking needs is probably a job for an under-sink system. If you want to filter your water for three sinks or more, or you want to include the water for your bath, washing machine or other appliances, a more comprehensive, whole-home system is the better choice.

Naturally, King Water Filtration offers both under-sink and whole-home systems that will meet your needs and budget. Our systems require zero maintenance and are backed with up to a 20-year warranty and a 30-day money back guarantee. We even have a new, ecofriendly filtration system that doesn’t use any electricity. If you’re interested in setting up a water system today, contact us at 1-855-957-2166 or schedule a consultation via our contact form. You can also purchase King Water Filtration systems at Home Depot.