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Reverse osmosis systems give you cleaner, more pure water by removing dirt, chemicals, microorganisms, heavy metals, and other contaminants and impurities. The This Old House Reviews Team has found the best reverse osmosis systems on Amazon to fit your sink. These are our top picks.
Top 5 Reverse Osmosis Systems
- Best American-Made System: APEC Water Systems Reverse Osmosis System
- Best Water Taste: iSpring Under-Sink Reverse Osmosis System
- Best Leak Detection: Express Water Reverse Osmosis System
- Best Tankless System: Waterdrop Reverse Osmosis Filtration System
- Best Countertop System: AquaTru Countertop Water Filtration Four-Stage System
Compare Top Reverse Osmosis Systems
| Product | Weight | Capacity | Installation | Warranty |
|---|---|---|---|---|
| APEC Water Systems Reverse Osmosis System | 25 pounds | 4 gallons | Under-sink | 1 year with 2-year warranty available upon registration |
| iSpring Under-Sink Reverse Osmosis System | 20 pounds | 75 gallons | Under-sink | 1 year |
| Express Water Reverse Osmosis System | 11.8 pounds | 4 gallons | Under-sink | 1 year |
| Waterdrop Reverse Osmosis Filtration System | 31 pounds | 400 gallons | Under-sink | 1 year |
| AquaTru Countertop Water Filtration Four-Stage System | 22.8 pounds | 3 quarts | Countertop | 1 year |
| Product | Weight | Capacity | Installation | Warranty |
Best American-Made System: APEC Water Systems Reverse Osmosis System
APEC Water Systems Reverse Osmosis System
- $199.95
Prices taken at time of publishing.
Pros and Cons
✔ Comes with everything you to need to install it, including a drain saddle and food-grade tubing
✔ Can purify mineral-rich well water
✔ The fittings have stainless steel teeth for gripping
✘ Only has a four-gallon capacity
✘ Requires power tools for installation
What Customers Are Saying
Reviews complimented the efficiency of this system, which multiple customers said saved them more energy and money than previous reverse osmosis systems they had used. However, some customers weren’t satisfied with the system’s installation process, which required a cordless drill to drill holes.
Best Water Taste: iSpring Under-Sink Reverse Osmosis System
iSpring Under-Sink Reverse Osmosis System
- $279
Prices taken at time of publishing.
Pros and Cons
✔ Comes with a 100% satisfaction guarantee from the manufacturer
✔ Includes instructional videos and customer support to make the installation process easier
✔ Has a fine reverse osmosis membrane
✘ Some customers have mentioned leaking
✘ Has been issued a Proposition 65 warning from the California government, indicating that it may expose users to chemicals
What Customers Are Saying
Customers frequently complimented how easy to install this system was, with the process being easy enough for even those with no DIY experience to manage. Reviewers who rated this product poorly complained that the system’s parts leaked.
Best Leak Detection: Express Water Reverse Osmosis System
Express Water Reverse Osmosis System
- $199.99
Prices taken at time of publishing.
Pros and Cons
✔ Has a high temperature rating of 100 degrees Fahrenheit
✔ Has a lightweight body that’s ideal for fragile plumbing systems
✔ Can be customized with add-ons, such as deionization filters
✘ Has a slower water recovery than competing systems
✘ Some customers said that the water storage tank broke down
What Customers Are Saying
Customers praised this RO’s filter design because the swivel connections allowed for quick-change filters without removing any tubing. However, dissatisfied customers complained about the system’s maintenance process, which required regular intensive cleaning in addition to filter changes.
Best Tankless System: Waterdrop Reverse Osmosis Filtration System
Waterdrop Reverse Osmosis Filtration System
- $645.99
Prices taken at time of publishing.
Pros and Cons
✔ Comes in multiple finishes
✔ Comes with water filter system detection that tells you when the filter needs to be replaced
✔ Offers a massive water flow rate of up to 400 gallons per day (GPD)
✘ Is priced significantly higher than many other systems
✘ Has a heavier weight than most competing models
What Customers Are Saying
Customers praised this system’s effectiveness. Several customers purchased tap water testing kits to determine the efficiency of this system and found that the water it provided was comparable to filtered bottled water. However, some customers found its faucet to be flimsy.
Best Countertop System: AquaTru Countertop Water Filtration Four-Stage System
AquaTru Countertop Water Filtration Four-Stage System
- $449
Prices taken at time of publishing.
Pros and Cons
✔ Doesn’t require plumbing installation
✔ Uses specialty filters that may last up to two years before a replacement filter is needed
✔ Purifies one gallon of tap water in as little as 12 minutes
✘ Provides four stages of filtration, which is fewer levels than the other options in this review
✘ Priced higher than many direct-connection systems
What Customers Are Saying
Customers said that this reverse osmosis system was strong enough to remove even solid particles from the gallons of water it filtered. However, customers who weren’t satisfied with their purchase complained that it stopped working after a short period of time.
Buyer’s Guide
A reverse osmosis water filtration system is an easy form of water treatment. It works by removing contaminants from your tap water during the filtration process. This buying guide will help you pick the best reverse osmosis system for your sink.
Size
Reverse osmosis systems can vary greatly in size. Most models are designed to be stored underneath a sink, although countertop versions also exist. Measure how much space you have under or around your sink before purchasing a reverse osmosis system.
Tank
Some reverse osmosis systems have a tank that stores water before it’s transferred to your sink. Others forgo the tank to save space. The type you purchase should depend on how much space you have in your kitchen.
Filter Type
Reverse osmosis systems move water through three to six filters to remove contaminants. Common types of filters include:
- Sediment: This type of filter removes dirt and other large particles.
- Carbon: This type removes chlorine.
- Reverse osmosis: These filters remove particles that are larger than water molecules.
- UV: This type of filter kills microorganisms.
- Targeted: These filters remove specific types of contaminants, such as nitrate or fluoride. They’re only needed if these contaminants are present in large quantities.
- Remineralization: This filter introduces calcium and magnesium into the purified water to balance its pH.
Capacity
The amount of water that a reverse osmosis system can purify at one time is typically measured in gallons. Choose a capacity based on how much water you and your family use in a day. For example, if you live alone, a system that purifies four gallons of water will be enough. However, if you have a family of five, you will need a reverse osmosis system that can purify at least 20 gallons of water.
Safety Features
Some reverse osmosis systems have built-in features to ensure that they run smoothly. Common features include leak detectors and filter replacement indicators.
Water Pressure
In order for a reverse osmosis water filter to work properly, it should have at least 50 PSI. RO water filters with above an 80 PSI are ideal for homes where the water supply lacks pressure.
Frequently Asked Questions
How does a reverse osmosis system work?
A reverse osmosis system removes dirt, bacteria, and chemicals from your drinking water. It does this by passing water through a series of filters that each target a specific contaminant. Since the filters are semipermeable membranes, they allow water to pass through them while trapping undesirable molecules. The resulting water is purer than standard tap water.
Why do I need a reverse osmosis system?
A reverse osmosis system can provide your whole house with healthier and better-tasting water. However, it’s especially important to use a reverse osmosis system if you live in an area with poor water quality.
How often do I need to replace the filters in my reverse osmosis system?
Replace the filters in your reverse osmosis system at least once per year. If a filter gets clogged or damaged, replace it sooner. Some reverse osmosis systems have warning systems that tell you when a filter is failing or nearing the end of its life.
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