Under Sink Water Filters

Find your cartridge model number

Under sink cartridges are made to fit a specific housing or system, so the safest way to shop is by model number. Look for it on the cartridge label, the housing or the system manual, for example InSinkErator F-1000, GE FXULC or Everpure H300. Then search that number here. If the label is worn, the brand and model are often printed on the housing cap. Systems with two or more cartridges need each one replaced with its own matching model.

Micron ratings

Some cartridges list a micron rating, such as the 5 micron Rainfresh FC100 and UC205. A lower micron number means the filter catches finer particles.

Under sink water filter FAQs

How do I choose an under-sink water filter?

To choose an under-sink water filter, decide what you want to reduce, then check which NSF/ANSI standards its listing names. Standard 42 covers aesthetic issues such as chlorine taste and odour, 53 covers health-related contaminants such as lead and cysts, and 401 covers emerging compounds such as some medications. For a replacement cartridge, match the model number on your current cartridge or housing.

Can I install an under-sink water filter myself?

A licensed plumber is the safest choice to install an under-sink water filter system, because it connects to your water pipes and some models need a 1/2 inch hole drilled in the counter for their own faucet. Rainfresh recommends a professional for drilling granite. Replacing the cartridge in a system that is already installed is simpler; follow the steps in your system's instructions.

How often should I replace an under-sink water filter?

Many under-sink water filter cartridges are replaced about every 6 months, or sooner if water flow drops or taste and odour return. InSinkErator recommends replacing its F-1000 cartridge every 6 months, and Rainfresh says to replace the CF2 pre-filter in its drinking water systems every 6 months, while its 1M ceramic cartridge lasts about one year. Note the install date on the housing.

Does an under-sink water filter need its own faucet?

Some under-sink water filters use your existing kitchen faucet and others need their own faucet. The Rainfresh UC205 attaches to the kitchen faucet, while Rainfresh's System 2 comes with a separate chrome faucet, and Rainfresh does not recommend connecting that system to the kitchen faucet because of possible cross-contamination from hot water and reduced flow. Check the system's instructions before buying.

Do under-sink water filters remove fluoride?

Under-sink carbon and sediment water filters cannot adequately remove fluoride, and Rainfresh states that its ceramic System 2 does not reduce fluoride. The Manitoba government lists reverse osmosis, distillation, anion exchange and activated alumina media as methods that can remove it. Health Canada's maximum acceptable concentration for fluoride in drinking water is 1.5 mg/L, so check a water test first.

What is the difference between an under-sink carbon filter and a reverse osmosis system?

An under-sink carbon filter reduces chlorine, taste and odour, while a reverse osmosis system adds a membrane fine enough to also remove dissolved salts. Rainfresh explains that home reverse osmosis systems use sediment and carbon pre-filters to protect the membrane, and that part of the incoming water leaves as reject water. RO replacement cartridges are in reverse osmosis water filters.

Will a Swift Green compatible under-sink water filter fit my system?

A Swift Green compatible under-sink water filter fits when the original cartridge number it replaces matches the cartridge in your system. Swift Green engineers each filter to match the design and specifications of the original brand's part, though its filters are not made or sponsored by those brands. If a listing does not show your number, get part-finding help.