The 2025 Buyer’s Guide to Reverse Osmosis
Water is at the heart of our health and our homes — we use it to drink, cook, clean, and so much more. That’s why it’s important to make sure the water in our homes is as clean as possible. If you’re looking to improve your water quality, a reverse osmosis system can help remove contaminants and provide pure, healthy water for you and your family. Read through our Reverse Osmosis Buyer’s Guide to see if a reverse osmosis system is right for your home.
What Is Reverse Osmosis and How Does It Work?
A reverse osmosis system (also known as an RO system) is a water purification technology that uses a semi-permeable membrane and other filters to remove anything larger than water molecules, including unwanted ions and larger particles from water. Reverse osmosis works by applying pressure to water on one side of the membrane, forcing it through the membrane while leaving contaminants behind. The purified water passes through the membrane while the concentrated contaminants are flushed away.
You can compare reverse osmosis to the process of making drip coffee: a coffee filter holds the coffee grounds as hot water is poured on top, allowing only the liquid coffee to flow through. Likewise, the RO membrane traps contaminants so that clean water can pass through to the other side.
In addition to the membrane, pre-filters and carbon filters are often used to remove debris, dust, and other larger sediment to make the reverse osmosis system more effective. The reverse osmosis membrane’s pore size is approximately 0.0001 microns in size.1
Once the water has passed through all the filters, it flows into a tank and is stored there until it’s needed. When the tap is opened, the pressure of the water in the tank helps release it from the tank. Once the tank has been drained to a certain point, the filters are triggered to continue filtering water and refill the tank, so the water that you use is continuously being replaced.
Most RO systems are designed to be installed at the point of use (like your sink) rather than the home’s main water line.
Tankless reverse osmosis systems are a good option if you want to save space under your sink since they do not have a storage tank. These units have an electric pump that provides the pressure needed to deliver water once it has been treated through the reverse osmosis membrane. They also produce less water waste than tanked systems because they can deliver a continuous supply of filtered water without needing to refill a tank.
What Is the Difference Between Reverse Osmosis and Water Filtration?
Filtration is an umbrella term that refers to the process of passing water through a porous material to remove particles and impurities. Water filtration usually refers to the removal of suspended solids, sediment, bacteria, and some chemicals, but typically not dissolved salts, minerals, or metals. Reverse osmosis is a type of advanced water filtration that uses pressure to force water through a semi-permeable membrane. This membrane has very small pores and can reduce impurities in the water, including dissolved solids, minerals, and metals. Reverse osmosis membranes have the smallest pore size of any other type of filtration, making RO one of the most effective forms of water filtration available.5
To put it simply, filtered water refers to any water that has been treated to reduce the level of impurities in the water. Reverse osmosis is an advanced, multi-stage form of water filtration.
What Does Reverse Osmosis Remove?
Tap water contains impurities like chemicals that can make your water taste unpleasant and could impact the flavour of your drinks and cooking.1 Our reverse osmosis systems are highly effective at reducing the following:
- Microplastics
- Protozoa such as Cryptosporidium or Giardia2
- Bacteria like Campylobacter, salmonella, shigella, and E. coli3
- Viruses such as enteric, hepatitis A, norovirus, and rotavirus3
- Common chemicals such as metal ions, sodium, chloride, copper, and chromium4
- Hazardous heavy metals like lead and mercury — although most modern municipal systems already filter these out from water, they may still be present in older systems or non-municipal sources
- Other chemicals such as arsenic, fluoride, radium, sulfate, barium, calcium, magnesium, potassium, nitrate and phosphorous
Should I Be Concerned About Reverse Osmosis Systems Removing Important Minerals from My Water?
This shouldn’t be a cause for concern because, in Canada, water is a minor source of the minerals we need for health — the majority are consumed through food. According to Government of Canada guidelines, if you consume a reasonably balanced diet, you do not need to take mineral supplements when drinking water treated with reverse osmosis.
Filters in Reverse Osmosis Systems
Reverse osmosis systems have filters that treat the water before and after the principal reverse osmosis membrane. Below, we explain the filters in ROs and how they work to provide purified water.
Tanked
A 4-stage reverse osmosis system consists of the reverse osmosis membrane and three other filters:
| 1. Pre-Filter (also known as a Sediment Filter) This filter provides the first layer of cleaning where large debris, such as dirt and dust, are removed. |
| 2. Carbon Filter #1 This filter reduces bad taste, odour, chlorine, chloramines, and volatile chemicals. |
| 3. Reverse Osmosis Membrane The main filter in the RO system significantly reduces the contaminants in the water. The RO membrane reduces total dissolved solids (TDS)6, chemicals, and heavy metals.7 |
| 4. Carbon Filter #2 This filter adds an extra layer of cleaning that further reduces any lingering bad taste, odour, chlorine, chloramines, and volatile chemicals. |
Tankless
A tankless reverse osmosis system uses an electric pump to provide instant RO-treated water without the need to store the water in a tank. The tankless RO system that Enercare provides is made up of two stages and the pump:
| 1. Pre-Filter (also known as a Sediment Filter) This filter provides the first layer of cleaning where large debris, such as dirt and dust, are removed. This is usually a 5-micron filter. |
| 2. Reverse Osmosis Membrane The main filter in the RO system significantly reduces the contaminants in the water. The RO membrane reduces total dissolved solids (TDS)6, chemicals, and heavy metals.7 |
Are More Filters Better?
The main filter in the RO system is the reverse osmosis membrane. The membrane is essentially the heart of the system and will remove most contaminants. A 3-stage reverse osmosis system is the core of an RO system with a pre-filter, carbon filter, and reverse osmosis membrane. This system has a contaminants rejection rate of 97.5%.8 You can think of the additional stages as assistants to the membrane. Each added filter will reject more contaminants but to a lesser degree than the core three stages.
Though extra stages can help extend the lifespan of the RO membrane, it’s important to remember that more aren’t always better. Below are some of the benefits and drawbacks of more RO stages.
Benefits:
- Enhanced Filtration: More filters means that the later filters may catch anything missed by the first filter. They can give you water that may have a lower total dissolved solids (TDS) count than a unit with fewer filters — in other words, purer water.
- Improves Taste and Odour: Additional filters, especially carbon filters, will remove more chlorine from the water, which means your water will both smell and taste better.
- Longer Filter Life: Having more filters puts less burden on any one filter, and the RO membrane will also have fewer contaminants to filter out. With a lower workload, your RO membrane can go longer without being changed.
Drawbacks:
- Higher Cost: More filters mean more replacement, and in some instances, multiple filters need to be changed at the same time. If you own your RO system, it can become costly to keep up with all the filter replacements. When you rent your system from Enercare, the higher replacement cost isn’t an issue since we offer free filter replacement for the lifetime of the unit.*
- Reduced Water Flow Rate: The more filters an RO system has, the more membranes that water will need to pass before it collects in the tank. The increase in barriers can cause a reduction in the water flow rate, which means the tank will take longer to fill up. The time between full takes will increase the more stages a unit has.
- Incremental Returns: More stages are not necessarily better because the first stages do most of the heavy lifting. The benefit of each consecutive filter is reduced after each stage since there are fewer and fewer contaminants remaining in the water to be filtered out. For homes with especially poor-quality water, more stages could be helpful in filtering a higher number of contaminants.
Overall, the number of stages in your RO system should be guided by the quality of water and the needs of your home. Having an Enercare expert test your water and recommend a solution for your water needs will ensure you get the best water for you and your loved ones.
How Often Do I Need to Replace the Filters in My RO System?
Tanked Reverse Osmosis
| Filter Type | Replacement Time |
|---|---|
| Pre-Filter | 1 year |
| Carbon Filter #1 | 1 year |
| Reverse Osmosis Membrane | 3 years |
| Carbon Filter #2 | 3 years |
Tankless Reverse Osmosis
| Filter Type | Replacement Time |
|---|---|
| Pre-Filter | 1 year |
| Reverse Osmosis Membrane | 3 years |
How Long Does a Reverse Osmosis System Last?
A reverse osmosis system will typically last around 10-15 years if properly maintained by changing the filters according to manufacturer guidelines. If you live in an area with hard water, pairing your RO system with a water softener installed on your home’s main water line can help extend the life of the reverse osmosis membrane. While RO systems do remove some of the minerals found in hard water, the process of filtering these minerals can still wear down the membrane and reduce its lifespan.
Since hard water build-up can cause appliances to perform less effectively, a water softener can also improve the efficiency of your other equipment, like your dishwasher, washing machine and water heater, by reducing limescale build-up.
Reverse Osmosis Systems Cost
| RO System Type | Enercare’s Monthly Rental Rate + HST | Enercare’s Purchase Cost (Including Installation) + HST |
|---|---|---|
| Tanked System | $29.01 | $1,679.00 |
| Tankless System | $33.31 | $2,200.00 |
Renting vs. Buying
| Renting | Buying | |
|---|---|---|
| Installation | Professional installation by Enercare so you know it’s done right | Professional installation by Enercare so you know it’s done right |
| Repairs | Coverage for repairs for the life of the equipment* | Repair coverage not included |
| Service | Free service calls for any issues with your unit* Free filter replacements for the lifespan of the unit* | Responsibility for maintaining and servicing the equipment is with the homeowner (including purchasing filters) |
Give us a call to schedule a free in-home consultation. An Enercare specialist will perform a water quality test to help you determine if a reverse osmosis system is right for your home.
Call 1-855-514-6485Common Reverse Osmosis Troubleshooting Issues
- Clogged Filters: Over time, the sediment and carbon filters in the system can become clogged as they remove impurities such as dust, dirt, and metals from your water. Clogged filters can also cause bacteria to accumulate, which could become a health risk to you and your family. Changing your filters regularly will ensure that your system is always working properly and providing the best water it can.
- Low Water Pressure: Reverse osmosis systems require sufficient water pressure to function efficiently. If the incoming water pressure is too low, the system may produce water slowly or not at all. A booster pump may be needed to increase pressure. If you have a tankless RO, low water pressure could also be the result of the system’s pump malfunctioning and not passing the water through at the necessary pressure.
- Leaks: As with any water system that has numerous connected parts, there is always the chance that a leak can develop over time. These leaks can be from installation or from tubes not being secured back in place properly when changing the filters.
- Taste and Odour: This is typically a result of your filters having reached the end of their lifespan. Ensuring that your filters are replaced regularly will help keep your water clean and tasting great by effectively removing chlorine and other chemicals that can give the water an unpleasant smell and taste.
To achieve peace of mind, consider renting a reverse osmosis system with Enercare. Our experts will install and maintain your equipment to ensure it’s always working at its very best. We’ll even ship filters right to your door when they need replacing.
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