If you want pure water, nothing beats a reverse osmosis system. Install one of these clever gadgets and you’ll never need another filter. But with so many different options on the market, how do you choose the one that’s right for you?
Here, we check out seven of the best reverse osmosis systems on the market today. Then we take a look at how to select the features that will make sure it works for your household.
If you don’t want the hassle of regularly changing filters, APEC’s reverse osmosis system is well worth considering.
This uses super-capacity filters so you’ll be able to go longer between changes. The filters for the first three stages of treatment are designed to last around a year. You’ll need to replace the full set once every three to five years.
The water passes through five different filtration stages in this system.
The second and third stage filters use large double blocks of carbon. The large surface areas maximize the contact time between the water and the purifying carbon. These stages will remove chlorine and unpleasant tastes and odors.
The fourth stage is the reverse osmosis membrane. This filters out 99 percent of total dissolved solids (TDS), including arsenic, lead, nitrates, volatile organic compounds (VOCs) and heavy metals.
The final stage is a coconut carbon filter, which removes any residual impurities or flavors.
The result is exceptionally clean water, free of any chemical tastes.
The system is fast too. The large filters purify water twice as quickly as systems using smaller cartridges.
It comes with an attractive lead-free chrome faucet that will look great in any contemporary kitchen. It’s designed to resist leaking and rotates through 360 degrees for ease of use.
The whole package comes with a two-year manufacturers’ warranty.
So far so good. But is there anything to watch out for?
Well, this system does require the water pressure of your feed to be no more than 85 psi. And the flow rate isn’t that fast, particularly when the tanks aren’t full.
And note that if you need 3/8 inch tubing, you’ll have to buy an upgrade to get it. That will cost you almost twenty percent of the price of the system.
Five stage system removes up to 99 percent of contaminants
Large capacity filters mean you’ll need to change them less often
Includes an attractive lead-free faucet
The flow rate isn’t particularly fast
You’ll need to pay extra if you require 3/8 inch tubing.
Express Water’s reverse osmosis system is another that uses a five-stage filtration process. But it’s a little over half the price of the one from APEC Water Systems. So why the difference?
Well, at first glance the two systems look very similar.
Express Water’s RO system also has a sediment filter as the first stage of treatment. That’s followed by a second and third stage that uses a carbon block and carbon granules to remove chlorine, odors, and VOCs.
Then it’s on to the fourth stage – again, this is the membrane that removes other contaminants. Express Water’s system has also been tested and found to remove up to 99 percent of them.
Finally, there’s an activated carbon filter to mop up any residual traces of contaminants and smells.
It also includes a fast-flow faucet, delivering up to 0.8 gallons per minute.
The main difference between the systems – and the explanation for the difference in price – is the size of the filters. These are much smaller than the ones you’ll get with the APEC system, so you’ll need to change them more regularly. Expect to do the job about once every six months.
You will, though, receive an extra set of filters in the package. That means enough to last for around a year – making this a very competitively priced option.
It’s also easy to customize. It uses standard quick-connect fittings, so you can add or remove filters as you wish.
It’s small enough to be installed under your kitchen sink, or you can keep it in a remote location. (Bear in mind you may need extra tubing, depending on how far it is from the faucet.)
Your water pressure will need to be between 40 and 80 psi for it to work effectively. So depending on your supply, you may need to invest in a booster or regulator.
It’s compatible with either 3/8 inch or ½ inch connections. Just make sure that you insert the tubes fully into the fittings during installation. If you don’t push them in hard, you may find you end up with leaks.
Five stages of filtration to remove up to 99 percent of contaminants
Standard quick-connect fittings allow easy customization
Comes with an extra set of filters
You’ll need to change the filters more often than with large-capacity models
Push the tubes into the fittings hard, or they may leak.
If you’re worried about reverse osmosis water being demineralized and acidic, Home Master’s system is well worth a look. This puts water through no fewer than seven stages of treatment, including replacing the calcium and magnesium lost during RO.
It will remove up to 99 percent of contaminants, including sediment and heavy metals.
The filter element and housing are made as a single unit and are completely disposable. That makes changing the filters easier and more hygienic, as you’ll never have to touch the contaminated media.
You’ll need to replace them after every 2,000 gallons. Depending on your rate of water use, that’s roughly once a year. It’s easy to do – just unscrew the used ones by hand, and screw in the new ones. You won’t need to use a wrench.
The package also includes a “fast flow” kit, which will double the speed of flow to your faucet.
One other issue with RO systems is that they do produce wastewater. With this system, efficiency is improved by the inclusion of a non-electric permeate pump. This cuts the amount of wastewater produced by up to four-fifths.
At the same time, the pump increases the amount of purified water by 50 percent. And it marginally improves the quality of the treated water by dealing with a problem known as “TDS creep”. (This happens when water is under low pressure in the system, increasing the levels of total dissolved solids.)
Also included is a faucet. It’s not the best looking one out there, and is a little flimsy for our liking. But it does give a good, fast flow.
We’ve heard of different experiences with installation. The manual and video are clear and helpful, but if your sink set-up isn’t standard, the process may take a while.
Helpfully, the purification unit, which includes the RO membrane and filters, comes pre-assembled. Also included are a storage tank, drain saddle, RO faucet adapter, and an adapter for a 3/8-inch feed. And the whole package comes with a five-year limited warranty for peace of mind.
7 stage water treatment, including remineralization
Fast flow rate
Permeate pump reduces wastewater
The faucet included in the package is a bit flimsy
Installation can be tricky if your sink set-up isn’t standard.
iSpring’s RCC7AK system removes up to 99 percent of 1,000 contaminants including chlorine, arsenic, fluoride, asbestos, and sodium. It also removes up to 98 percent of lead.
And like the Home Master system, it recognizes that RO removes good minerals as well as bad pollutants. And it puts them back in again.
The treatment takes place over six stages. The first three are the “pre-filter” stages, before the water passes through the RO membrane. The first stage catches sediment, and this filter is helpfully housed in a clear case. That means you’ll be able to see when it needs to be changed.
The second and third treatment stages use carbon granules and a carbon block. They remove the odor and taste of chlorine from city water.
The fourth stage is the membrane, which removes the bulk of the nasties. This is followed by a final activated carbon filter to remove any remaining odors or unwanted tastes.
The sixth stage is an alkaline filter. This replaces the good minerals lost during the RO process. It gives a better taste, as well as making the water less acidic. Anyone with a sensitive stomach will appreciate the difference.
You’ll need to replace the filters every six to twelve months. The precise frequency will depend on the quality of your water and your rate of use. The RO membrane will last longer. Expect to replace that every two to three years.
The system comes with an attractive high spout faucet with a brushed nickel finish. It’s a good quality piece of hardware, with a lead-free brass body and a ceramic disc to prevent leaks.
The system will fit under most kitchen sinks, and installation is straightforward. You’ll just need to push the tubing half an inch deep into the connectors, and lock it. You won’t need any threading pipes. A feedwater adapter allows it to be used with either ½-inch NPT or 3/8-inch COMP tubing.
Spare fittings and O-rings are included in the package. Expect installation to take up to a couple of hours. The instructions are easy to follow, and there’s a video to help too. And if you really get stuck, you can access technical assistance by phone.
One thing to watch out for is that the water pressure requirements here are more restrictive than some. You’ll need incoming pressure of between 45 and 70 psi for the system to work effectively.
And the tap valve for the drain isn’t to everyone’s liking. It’s plastic and some people have found it tricky to use.
Six stage treatment includes remineralization
Package includes a good quality faucet, spare fittings, and O-rings
Easy to install, with telephone support available if needed
You’ll need water pressure of between 45 and 70 psi for this to work effectively
The tap valve for the drain isn’t very easy to turn.
The RO-505 model from Global Water is one of the most keenly priced RO systems on our list. So what do you get for your money?
Well, this is a five-stage system, using a combination of different media to remove up to 99 percent of contaminants.
It follows the standard sequence: filter sediment first, followed by two carbon-based filters, the membrane, and a final filter.
The sediment filter is made of polypropylene and will remove particles down to five microns in size. That means you can say goodbye to sand, rust or limescale in your water.
The second filter is coconut shell activated carbon. It will remove chlorine, organic compounds, and VOCs. And it will take away unpleasant odors at the same time.
The third filter is a carbon block and will remove finer particles of contaminants down to five microns. It also prevents your water from being cloudy.
The fourth stage is the RO membrane itself, which will deal with heavy metals and other chemicals. The water then passes through a fifth and final “polishing” filter to remove any lingering tastes and odors.
There’s no remineralizing filter, though, so you’ll need to add one separately or cope with slightly acidic water.
The system will cope with water pressure between 40 and 80 psi.
It comes with a faucet and quick-connecting fittings. These will secure in place without the need for any clips. Just make sure you’ve connected the system up correctly before you push them into place. Once they’re fully pushed in, they won’t come out again!
Installation isn’t the most straightforward – the instructions could usefully have a bit more detail. But take it slowly and you’ll get there in the end.
And watch out for the Teflon tape included in the package. We’d recommend wrapping it around several times – or perhaps investing in some better quality stuff yourself.
Five stages filtration at a very competitive price
Includes a faucet
Quick connect fittings mean you won’t need any clips for installation
Installation instructions could be more detailed
The Teflon tape included in the package isn’t the best quality.
If you like the idea of reverse osmosis but don’t want to install an under-sink system, consider AlcaPure’s countertop model. This attractive unit doesn’t require any installation at all. Just add water to the pitcher, wait 15 minutes, and pure water will be dispensed to a container at the top.
It takes up surprisingly little countertop space. It’s 9.5 inches wide, 14.5 inches deep and 16.5 inches tall. Because water is added and dispensed at the front, you won’t need any additional clearance above or to the sides.
It’s efficient too. It has a recovery rate of 50 percent – in other words, half of the water volume you add will be returned as purified water. That’s much more efficient than most RO systems, which commonly have a purified to wastewater ratio of 1:3 or 1:4.
There are some compromises with a system of this kind. There are fewer filtration stages than with under-sink models. There’s a sediment filter, a carbon block filter, a membrane, and a final filter to replace lost calcium and magnesium.
That’s at least two filters fewer than other RO systems incorporating a remineralizing stage. The system will still, however, remove up to 99 percent of contaminants, including fluoride, chlorine and heavy metals.
The filters will need to be changed once a year. An indicator light will blink when it’s time, so you won’t need to worry about forgetting. The membrane will need to be changed every two years. A steady red light will remind you of that too.
With this system, you’ll only get half a gallon of purified water at a time, rather than a continuous supply. But for some people, that may be a price worth paying for avoiding the hassle of installation. And you won’t lose any space in your under-sink cupboard either.
If you’re concerned about the levels of wastewater produced by many RO systems, Greatwell’s tankless option is worth a look.
This produces a gallon of wastewater for every 1.5 gallons of purified water. That’s about a quarter of the wastewater produced by other RO systems. It produces a water flow of between 0.3 and 0.4 gallons per minute.
It’s designed to sit beneath your sink, where it will take up less space than other systems too. That’s because it combines three filters in one. The first filter combines two polypropylene sediment filters with a carbon filter. It will remove sand and rust, as well as chlorine tastes and smells.
The RO membrane will remove up to 99 percent of 1,000 contaminants including arsenic, lead, and fluoride.
Finally, an activated carbon filter removes residual flavors and odors.
The space-saving design does, though, come with some compromises on water quality. The levels of total dissolved solids after treatment are higher than with many other RO systems.
A lead-free stainless steel faucet is included, but you can also connect the unit to your refrigerator’s ice maker. (You’ll need to purchase extra tubing to do that.)
All the filters are housed in a smart container. There’s no guesswork needed on when to change them. Indicator lights on the front of the unit show when each filter needs to be changed. Wheels on the bottom of the unit make it easy to move it in and out of tight spaces.
The design also minimizes the number of connections, making installation simpler. We have, though, heard a few complaints about the clarity of the instructions.
Produces lower levels of wastewater
Indicator lights show when each filter needs to be replaced
Doesn’t reduce total dissolved solids as much as other systems
The instruction manual isn’t as clear as it could be on installation.
Still feeling bewildered by the choice of systems? Don’t worry! We’re here to help. Read on for our guide to the questions to ask before picking your new RO system.
Do you want a system that replaces lost mineral content?
One of the big issues with RO systems is that they remove everything from your water. In most cases, that’s good. Surely the whole point is to remove contaminants? But they also remove some good minerals.
That matters for a couple of reasons. The first is that some people will find the taste of the water “flat”. The second issue is that the water will be slightly acidic. If you or someone in your household has a sensitive stomach, this may irritate it.
Some systems include a remineralization stage as standard. Others don’t. If they don’t, we’d always recommend adding in an extra remineralizing filter to improve your water quality. So take the cost and hassle factor of that into account when making your final choice.
Think about your space
RO systems vary in size. Some will sit under your sink, or in a remote location like a basement. If you want to put it under your sink, check the dimensions to make sure it will fit! And if you’re planning to put it somewhere remote, make sure you have sufficient tubing to connect it up.
An alternative is a countertop model. These require no installation at all and are easy to use. But remember, you’ll only have as much pure water as the machine can handle at any one time. So take a look at the capacity before you buy. And check the specifications to see how long it takes to purify a new batch.
Consider how much maintenance you’ll need to do
Different systems use different sized filters. That in turn means different periods of time between changing them. The larger the filter, the longer it will last before it needs to be replaced.
Remember to treat estimates of filter lifespans with caution. Exactly how long they’ll last will depend on the quality of your water, and on how much you use. Some systems have indicator lights to show you when to change them. That’s a useful feature if you’re not sure you’ll remember to check them.
Ready to choose your new system?
That brings us to the end of our review of the best reverse osmosis systems on the market right now. We hope it’s helped demystify the different features that are available, and helped you consider how they’ll work for you.
Our favorite is iSpring’s RCC7AK. It gives great results with that all-important remineralization stage. And the technical support for installation is second to none.
Whichever system you choose, investing in RO means you’ll never have to worry about water quality again. Good luck in making your choice – and happy shopping!