Under-sink water filters are easy to compare on price and hard to compare on what they actually remove. The label decides most of it. Here are four top-selling systems, what the certification marks mean, and the Health Canada advice to read before you buy.
Short on the label: Check This Label Before Buying An Under Sink Water Filter
Quick answer
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Check the package before the price. According to Health Canada, look for a filter tested to NSF/ANSI 53 with a lead reduction claim, plus NSF/ANSI 42. No federal rule requires testing or third-party certification in Canada, so the label is how you check.
A simple place to start: the Frizzlife SP99, ranked #11 in Under-Sink Water Filters when we checked. Its product page lists NSF/ANSI 42, 53 and 372 and a lead-free faucet in the box. Want a longer filter life? The Waterdrop 15UB is ranked #5 and lists up to 24 months or 19,000 gallons on municipal water.
Four under-sink water filters, by how you’ll use them
| Product | Best for | |
|---|---|---|
| Frizzlife SP99 under-sink water filter | Best for a kitchen where you want the lead standard (NSF/ANSI 53) listed on the page. #11 in Under-Sink Water Filters when we checked. The product page lists NSF/ANSI 42, 53 and 372, a 0.5 micron filter, a lead-free faucet in the box and a tested flow rate above 1.5 GPM at 60 psi. Skip it if you want to cut dissolved minerals: the page says it keeps minerals and doesn’t reduce TDS. | See price |
| Waterdrop 15UB under-sink filter with faucet | Best for adding a separate drinking-water tap. #5 in Under-Sink Water Filters when we checked. The product page says it’s certified by IAPMO to NSF/ANSI 42 and 372 and tested by a third-party lab to NSF/ANSI 53 for lead, with up to 24 months or 19,000 gallons of service life on municipal water. Skip it if you want to keep using your existing tap: it comes with its own faucet, and it connects to cold water only. | See price |
| Waterdrop 15UA under-sink filter | Best for a kitchen that wants lead testing listed and a long filter life. #2 in Under-Sink Water Filters when we checked. The product page lists IAPMO certification to NSF/ANSI 372 and 42, third-party testing to NSF/ANSI 53 for lead, and up to 24 months or 19,000 gallons on municipal water. Skip it if you fill big pots and want the fastest flow: its tested rate is 0.75 gpm at 60 psi. | See price |
| iSpring US31 3-stage under-sink filter | Best for fitting the faucet from above the countertop. #18 in Under-Sink Water Filters when we checked. Per the product page: three filter stages, up to 10,000 gallons or 12 months, a flow of 1 GPM and a 1-year manufacturer warranty. Skip it if lead is your reason to buy: the page says it was tested to NSF/ANSI 58 and doesn’t name NSF/ANSI 53. | See price |
Specs come from the retailer’s product pages and can change, so check the current page before you order.
What does NSF/ANSI certified mean?
NSF/ANSI standards are the performance tests a water filter is measured against. According to Health Canada, there are six for home treatment devices: 42 covers aesthetic effects such as taste and chlorine, 53 covers health effects such as lead, and 58 covers reverse osmosis. A certifier authorized by the Standards Council of Canada does the testing. Examples are CSA Group, NSF International, the Water Quality Association, UL and IAPMO. Certification covers only the claims the standard checked, and makers can make other claims too, so read which ones were verified.
How do you check a filter for lead?
- Look for a certification mark and a statement that the filter was tested to NSF/ANSI 53 with a lead reduction claim.
- Look for NSF/ANSI 42 testing for particulate reduction (Class I) as well. Health Canada recommends it because some particles can contain lead.
- A mark with a letter C in the lower left corner shows Canadian accreditation.
- If the claim isn’t on the package, check the certifier’s online directory or the maker’s performance data sheet. Waterdrop’s product pages suggest searching the model number on the certifier’s site.
Do you need an under-sink filter at all?
According to Health Canada, community drinking water that meets the guidelines doesn’t usually need more treatment for health reasons. If you drink well water, it advises testing your water regularly. A filter can still change the taste and cut chlorine.
Under-sink filter or reverse osmosis?
Reverse osmosis systems are certified to NSF/ANSI 58. According to Health Canada, they remove minerals such as calcium and magnesium, but water is a minor source of those minerals in Canada compared with food, so a balanced diet covers it. None of the four filters above is a reverse osmosis system.
Common questions
Will it remove bacteria or viruses? No. According to Health Canada, filters certified to NSF/ANSI 53 for parasitic cysts can help where water has Cryptosporidium or Giardia, but they won’t remove viruses or bacteria.
How often do I change the filter? Follow the maker’s instructions, as Health Canada advises, because maintenance keeps a filter working. The two Waterdrop pages list up to 24 months or 19,000 gallons on municipal water, and the iSpring page lists up to 12 months or 10,000 gallons.
Is certification required in Canada? There’s no federal requirement for testing or third-party certification, according to Health Canada, though some provinces or territories may have one.
Do I need a plumber? The product pages say no. Waterdrop lists push-to-connect fittings and a setup time under 3 minutes, and Frizzlife says it can be installed in 15 minutes with its video instructions. Check your own connections first: the Waterdrop pages describe 3/8 inch and 1/2 inch fittings and cold water only.
Before you buy
- Look for NSF/ANSI 53 with a lead claim, plus NSF/ANSI 42, on the package or product page.
- Search the model number in the certifier’s directory to confirm the claim.
- Check what’s in the box: faucet, hoses and adapters for your sink.
- Look up the filter-change schedule and the cost of replacement filters.
- Drink well water? Health Canada advises testing it regularly.
- Checking your home’s air too? Our radon testing guide covers the gas you can’t see.
Our top pick: Frizzlife SP99 under-sink water filter
Sources: Health Canada, Questions and answers on drinking water treatment devices; Health Canada, Infographic: Finding a drinking water filter; Health Canada, Drinking water and health: Treatment. Product details come from the manufacturers’ and retailer’s product pages, so check the current page before you order.
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