What is the difference between the 5, 6, and 7 stage versions?

The 5-stage system handles sediment, chlorine, heavy metals, and around 99% of TDS, ideal for most Canadian homes on municipal water. The 6-stage version adds alkaline remineralization. The 7-stage system adds UV sterilization, making it the best choice for well water.

Standard Reverse Osmosis System

Q: Does the Standard RO System take up a lot of space under the sink?

No, it is designed specifically for compact under-sink installation. The vertical profile keeps the unit out of the way and it comes with a stylish lead-free designer faucet in brushed nickel or chrome.

Q: How long do the filters last, and is it difficult to replace them?

Filters typically last 6-12 months. Replacing them takes about 5 minutes, just twist out the old cartridge and click the new one in, no tools required. The RO membrane lasts 2-3 years.

$375.00

49 in stock

Description

Standard Reverse Osmosis Filter

illi Water’s standard reverse osmosis system for home is a comprehensive water filtration solution for homeowners and businesses in Canada

What Is a Reverse Osmosis System?

A reverse osmosis (RO) water system is a multi-stage water filtration unit that easily fits under the sink. Using a semi-permeable membrane, it filters up to 99% of toxic impurities such as sediment, lead, fluoride, and chlorine. The advanced reverse osmosis process delivers crisp and clean water with a refreshing taste. For Canadian households that often struggle with contaminated and hard water, investing in a reverse osmosis system for your home is a wise decision that protects your family’s health.

How Does a Reverse Osmosis System Work?

A standard reverse osmosis system processes tap water through multiple stages to clean it of wide-ranging contaminants, including sediment, chemicals, bacteria, heavy metals, and unwanted tastes and odors. Below are the common stages in a standard reverse osmosis system.

Stage 1: Sediment Filter: Sediment filter strips the water of visible impurities like sand, silt, dirt, and rust.
Stage 2: Carbon Filter: Activated carbon reduces unpleasant tastes and odors, organic chemicals, and chlorine from the water.
Stage 3: RO Membrane: Pressurized water passes through a semi-permeable membrane to eliminate 99% contaminants like total dissolved solids (TDS), fluoride, and heavy metals.
Stage 4: Post Carbon Filter: Carbon filter captures any leftover odors or tastes in the water, giving it a fresh taste.
Stage 5: Alkaline Filter (Optional stage): Alkaline filter remineralizes the water with minerals such as magnesium and calcium, raising the water’s pH.
Stage 6: UV Sterilization (Optional stage): Ultraviolet (UV) light eradicates viruses, microorganisms, and bacteria from the water.
Stage 7: Advanced Carbon (Optional final enhancement): Specialized carbon block neutralizes contaminants like chloramines and hydrogen sulfide to deliver pure water.

Why Choose a Standard Reverse Osmosis Filter for Your Home?

A standard undersink RO system combines advanced technology with practicality to conveniently purify your tap water. Below are the reasons why it is the right fit for your home.

Standard, Widely Available Replacement Filters: Our systems function using industry-standard cartridges that are easily available online and in stores across Canada
Removes Up to 99% of Contaminants: Our undersink reverse osmosis filters eliminate a wide spectrum of contaminants, delivering pure water.
Advanced RO Membrane Technology: RO systems feature an advanced semi-permeable membrane that efficiently removes even dissolved impurities.
Reduces Chlorine Taste & Odor: Activated carbon filters absorb chlorine from the water, giving it a pleasant odor and fresh taste.
Eliminates VOCs, Heavy Metals & Pesticides: RO system attacks contaminants like agricultural runoff, lead, and volatile chemicals that cause serious health risks.
NSF/ANSI Certified Filtration Performance: Standard reverse osmosis filters are NSF/ANSI certified to uphold your trust and deliver optimal performance.
BPA-Free, Food-Grade Components: Every component of our RO water filters is made using fine-quality, BPA-free (bisphenol A) and safe materials, ensuring nothing harmful leaches into your water.
Lead-Free Designer Faucet (Multiple Finishes): The system boasts a stylish, lead-free faucet in brushed nickel or chrome finishing to elevate your kitchen’s aesthetics.
6–12 Month-Long Filter Life: Based on your water quality and usage, you’ll need to change the filters after 6 to 12 months only, making the upkeep simple.
Tool-Free Cartridge Replacement: You can easily change the cartridge by twisting the old one out and clicking in the new one without requiring any tools.
High-Efficiency, Low-Waste Operation: Modern reverse osmosis technology efficiently uses water, producing less wastewater, which makes it wallet- and eco-friendly.
Compact Under-Sink Design: The system has a compact, minimalistic design and discreetly fits under your kitchen sink, keeping the counter clutter-free.
Space-Saving Installation: The RO water filter comes in a contemporary, vertical style, taking up minimal cabinet space and leaving you with enough room to store other items.
Quiet, Continuous Operation: The unit works quietly in the background without interrupting your routine chores, creating a soft hum only when it refills the tank.

Why Trust Illi water for Reverse Osmosis Water Filtration?

We have been serving Canada with the best water filtration systems for over 30 years. Families and businesses across the country rely on us for their water filtration needs.

5-Year Warranty: We stand behind the quality of our standard reverse osmosis filters with a 5-year warranty that covers craftsmanship and defective parts of the system.
90-Day Satisfaction Guarantee: Try our undersink RO system, and if it doesn’t align with your needs, return it within 90 days for a full refund.
Free Shipping Across Canada: No matter where you live in Canada, we provide free shipping, making it convenient for you to access pure water.

What’s in the Box

1 x Standard Reverse Osmosis System (main filtration unit)
3 x Pre-installed filter cartridges (based on chosen stage: 5, 6, or 7)
1 x Designer lead-free faucet (finish options available)
1 x Tubing and connection fittings
BPA-free components throughout
1 x User manual with setup instructions
Warranty and 90-day trial documentation

Warranty

Our 5-year warranty protects your confidence and investment. It provides coverage for compromised materials and workmanship. However, it doesn’t cover cartridges, membranes, and filters. Rest assured, they will be in pristine condition when you receive your order.

Additionally, we provide a 90-day satisfaction guarantee in case our RO system doesn’t align with your water filtration needs. You can return your order within 90 days and get a complete refund.

To claim your warranty, or in case of queries, contact our support team at support@illiwater.com.

Delivery and Return

Every standard reverse osmosis filter comes with nationwide free shipping. It takes 1 to 2 business days to process each order. Once we ship your order, our support staff will provide you with tracking information to keep a check on your system.

We back every purchase with a 90-day satisfaction guarantee. If you aren’t satisfied with your system, return it within 90 days for a 100% refund. According to company policy, customers bear delivery costs in case of returning their order.

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Lower Cost Than Bottled Water with High-Efficiency Reverse Osmosis Membrane

Our standard reverse osmosis water system comprises a high-efficiency membrane manufactured using cutting-edge technology. The semi-permeable membrane has microscopic pores that only allow pure water molecules to pass through, leaving behind a concentrate rich in hazardous impurities. The semi-permeable membrane in illi Water’s RO filtration units efficiently utilizes water, unlike the conventional filters that waste tons of water during the purification process. As a result, you conserve more water and lower your utility costs as well. Besides being efficient, our reverse osmosis under-sink filter eliminates the need to get bottled water. With time, you save money and also reduce your plastic waste.

Let customers speak for us

from 122 reviews

The digital TDS display sold us on it

My husband and I are very tech-savvy and wanted to replace our old RO system with a more digitally advanced one. Luckily we found the tankless RO system by illi water. Its filtration power is quite solid, and we love how we can keep a check on the water quality with its digital TDS display.

Rosalie Gauthier

Tankless Reverse Osmosis System

07/28/2026

Lead free water and peace of mind

We have been using the Pentair Reverse Osmosis System by illi water and are quite satisfied with the system. It fits nicely under the sink and works quite efficiently. We switched to it 4 years back when we found lead in our water. After installing the illi water under-sink system, our water has been lead-free and the peace of mind we enjoy is unmatched.

Kevin Anderson

Pentair Reverse Osmosis System

07/28/2026

Sleek unit and my kids finally drink water

I wasn't happy with my previous water filter system. It was clunky, took up so much space, and the filtered water quality was mediocre too. A friend recommended illi water's tankless RO system and life has only been better ever since I made the switch. First things first, it's sleek and instantly adds a classy touch to my kitchen. Second, it performs really well. The water is tasty, clear and refreshing. My kids, who hated drinking water, now drink 6 to 8 glasses every day happily.

Sophie James

Tankless Reverse Osmosis System

07/28/2026

The 5 year warranty is not just marketing

The RO water systems by illi water are great, but what our family appreciates the most about the company is their 5-year warranty. We got a system from them and somehow it had an in-built fault. The company immediately replaced it with a properly functioning under-sink unit that has been with us for over 3 years now, and is working exceptionally well.

Noah Thompson

Pentair Reverse Osmosis System

07/28/2026

The formula preset is a lifesaver at 2am

I am quite picky about choosing products that directly affect my family's health. My previous water filtration system was good, but when I had my daughter, I decided to change the system for a few reasons. I wanted a system that offered more robust water purification and my previous system was a 4-stage purification unit. Secondly, I wanted something that could give me warm water on demand because preparing formula for my daughter at midnight isn't easy for a sleep-deprived mom. I researched online and asked my neighbours around and got some pretty good recommendations for illi water's RO Hot & Cold Water Dispenser. It has been a life saver. It has a 6-stage filtration process and delivers real clean water, and comes with different presets to get water on demand at your desired temperature. There is one for preparing formula and I just love it!

Laura Tremblay

RO Hot & Cold Water Dispenser

05/05/2026

Our office water finally tastes good

My boss only relies on tried and trusted brands when it comes to absolutely anything. My coworkers and I had been complaining of how weird the water in our office tasted, and while my boss was all ready to replace our filtration system, he asked for recommendations of good brands. My wife's office used illi water's systems so I suggested the brand to my boss. He asked around about it and after getting about a dozen positive reviews, he bought their Pentair under-sink for our office. It's been 8 months since that purchase and drinking water has become a happy, satisfying ritual at the office.

Jeremy White

Pentair Reverse Osmosis System

04/10/2026

Best decision I made after moving to Kingston

When I got a job in Kingston, Ontario, I shifted there and rented a small apartment. The city's tap water is quite hard and I realized that when I couldn't remove white stains from the sink, and my skin kept getting drier with time. I heard of illi water from a colleague and decided to use my savings to get their tankless RO filter. While the investment seemed pricier at first, it has been the best and most cost-effective decision of my life so far. My bottled water expenses reduced, my sink became stain-free, and honestly my skin feels soft and normal again. And the water tastes really good too.

Tanya Brown

Tankless Reverse Osmosis System

03/08/2026

Liked it enough to buy a second one for the office

I was using a famous water filter unit for both my office and home in Clarington, and I didn't realize how it was affecting the hydration needs and health of my family and work team until a team member complained of the water's foul taste. I asked my wife and kids about it, and they weren't too happy with the water's quality either. My wife had heard of illi water from her friend and asked me to try it out. Since it is a new brand, I was a bit apprehensive of how well it would perform, but after constant pressurization, I had to give in. Well, I mean, you know how wives are the boss at home. ;) Also, illi water offered a 90-day trial period which reassured me I could return the system if I wasn't satisfied with it. It has been a year since we got their standard RO under-sink water filter, and trust me, I never thought once about returning it. Six months back, I got the same one for my office too.

Liam Campbell

Tankless Reverse Osmosis System

02/06/2026

TDS went from 480 plus to under 25 ppm

If you have been to Regina, Saskatchewan, you would know the water quality is rough there. For years, my family has dealt with water that had a high sediment count, felt heavy, and tasted real bad. When a neighbour suggested I switch to illi water's under-sink reverse osmosis filter, I was a bit skeptical at the start, but my doubts were cleared in a few weeks. The TDS dropped to under 25 ppm from 480+ ppm, and the water tastes fresh and clean. This has been a wonderful decision we made.

Thomas Taylor

Tankless Reverse Osmosis System

02/03/2026

Filter alerts make life so much easier

Being a single mom, there is a lot on my plate. When it came to improving the water quality of my house, I wanted a hassle-free, good quality system that made my life easier, especially when it came to changing the filters on time. The tankless reverse osmosis system by illi water does exactly that. It provides timely filter life alerts that help me replace them on time and make sure my kids and I get a constant supply of clean, safe water.

Chantal Leblanc

Tankless Reverse Osmosis System

01/10/2026

Reverse Osmosis System For Home With Advanced Filtration

The best reverse osmosis system is one that addresses your water challenges and consumption needs. You can easily personalize our high-performing standard RO system, turning it into a 5-, 6-, or 7-stage RO unit based on your requirements.

Let’s walk you through the different customizations and the scenarios they suit best.

5-Stage RO System

Purpose: It uses 2 carbon filters, 1 sediment filter, an RO membrane, and a polishing filter to remove chlorine, heavy metals, sediment, bad tastes, and around 99% of TDS and bacteria.
Best for: This unit is perfect for homes with access to municipal water.

6-Stage RO System

Purpose: It builds on the 5-stage RO unit by adding an alkaline remineralization filter, which reintroduces minerals such as calcium and magnesium into the water to improve the water’s pH balance, making it smoother and tastier.
Best for: Ideal for Canadian homes in regions that have a higher TDS or chemical content in their water and families who prefer an alkaline and mineral-rich water.

7-Stage RO System

Purpose: It builds on the 6-stage RO system with the addition of a UV sterilization stage that destroys viruses, bacteria, and other microorganisms, making your water more hygienic and safer than ever.
Best for: Excellent for homes that use well water loaded with harmful contaminants and health-conscious homeowners who prefer microbiologically safe water.

Why Choose Our Undersink Reverse Osmosis Water Filter?

The standard reverse osmosis water system for home is space-efficient, easy to install and maintain, NSF/ANSI certified,
and it protects your health. It is the ultimate water filtration partner your home needs.

Space-Saving Design

Our undersink reverse osmosis system is engineered for contemporary homes that prioritize space-saving units. Contrary to outdated units with bulky countertop tanks, our RO system featuring a vertical design stays tucked under the cabinet, completely out of your sight. Your kitchen counter stays neat, providing you with sufficient space to organize your spice jars and cook comfortably. Since it is compact, it provides enough room for you to store cleaning supplies and other equipment in the undersink cabinet. With our RO water system, you get pristine water without compromising on your kitchen’s style and ergonomics.

What contaminants does the Standard Reverse Osmosis System actually remove?

The Standard RO System removes up to 99% of a wide range of contaminants, including lead, fluoride, chlorine, nitrates, VOCs, pesticides, herbicides, heavy metals like mercury and arsenic, and bacteria. The RO membrane filters dissolved solids at a near-molecular level, and the activated carbon stages handle taste, odour, and organic chemicals. If you're on well water or want extra protection, the 7-stage configuration adds UV sterilization to remove microorganisms.

What's the difference between the 5-, 6-, and 7-stage versions — which one do I need?

The 5-stage system handles sediment, chlorine, heavy metals, and around 99% of TDS. It's ideal for most Canadian homes on municipal water. The 6-stage version adds an alkaline remineralization filter that replenishes beneficial minerals such as calcium and magnesium, improving the water's pH and taste. The 7-stage system goes further with UV sterilization, making it the best choice for well water or households that want the highest level of microbiological protection. You can compare all three configurations here.

Does the Standard RO System take up a lot of space under the sink?

No, it's designed specifically for compact under-sink installation. The vertical profile keeps the unit out of the way so you still have room for cleaning supplies and other cabinet essentials. It won't touch your countertop at all, and it comes with a stylish lead-free designer faucet in brushed nickel or chrome to sit alongside your existing taps.

How long do the filters last, and is it difficult to replace them?

Filters typically last 6–12 months, depending on your household's water usage and local water quality. Replacing them takes about 5 minutes, just twist out the old cartridge and click the new one in, no tools required. The RO membrane lasts 2–3 years, and replacement cartridges are standard and widely available online and in stores across Canada, so you're never locked into a proprietary filter.

Is this system easy to install myself, or do I need a plumber?

Most homeowners install it themselves without any plumbing experience. The system comes with push-fit connections, tool-free cartridges, and a full step-by-step setup guide in the box. If you'd rather have it professionally installed, illi Water can connect you with certified technicians in your area.

Is the Standard RO System safe for kids, babies, and pets?

Yes. The system removes contaminants like lead, nitrates, and bacteria that pose the greatest risks to young children and animals. Every component, including the faucet is made from BPA-free, food-grade materials, so nothing harmful leaches into the water. The filtered water is also free of the chlorine taste that can put kids off drinking enough water throughout the day.

How quickly will my order arrive, and what if I need to return it?

illi Water offers free shipping on all orders across Canada, with orders processed within 1–2 business days and tracking details sent once dispatched. If the system isn't right for you, return it within 90 days for a full refund — no questions asked. The 5-year warranty covers defective parts and workmanship from day one. To arrange a return or warranty claim, contact support@illiwater.com.

Standard Reverse Osmosis System