No matter where you live or work, the water that you drink won’t be entirely pure and you’ll never know for sure what’s in your drinking water unless you have it tested in a lab. Who’s actually going to do this?
So to ensure that you have high-quality drinking water, a reverse osmosis (RO) water purification system is your safest bet. For those who simply want pure drinking water in their homes an under sink RO system is the best way to accomplish this. Though their other situations where pure water is needed and, for this, an under sink reverse osmosis system is not always the best. So this review is going to cover a variety of RO water purification systems: under sink; counter top and commercial reverse osmosis applications.
There’s a huge demand for RO systems that will provide safe, clean drinking water in our homes and this has made under sink reverse osmosis kits very popular. For most DIY guys, these systems are easy to install and maintain. They vary in price and efficacy and will generally use anything from 1 to 5 stages of purification. Though there are some RO systems that have a sixth stage which is really a remineralization process – adding essential minerals to soften the water by balancing the PH and, in some cases, adding minerals that are beneficial to our health. Some of the high-end RO systems have a seventh stage that use UV lights to ensure that there is absolutely no chance that any bacteria will be present in your drinking water.
Under Sink Reverse Osmosis Filters
The level of filtration and general quality will depend a lot on what you’re prepared to pay. Though you may end paying more than you need to unless you know what you’re getting. So this section of the review is going to help you choose the best under sink reverse osmosis system for your home.
1. APEC ROES 50 5 Stage
For a top quality, US made under sink RO system, the APEC ROES 50 comes at an incredibly reasonable price. You have the assurance that the tubing used is FDA food grade approved. Having been in the water purification business for over 20-years, the APEC brand is one that you can trust and depend upon. The reassurance of buying from an established brand means that you’ll always be able to get technical support, replacement parts,and top quality filters. The APEC ROES 50 has been certified by the Water Quality Association (WQA), so it’s been independently tested and verified.
The APEC ROES 50 is a very compact system, designed to fit under any sink – the tank measures 11 X 11 X 15 inches and the filtration system dimensions are: 16” X 5.2” X 17.5”. It’s easy to install and maintain, which is great news for homeowners who want to do it themselves. The push-in water fittings with stainless steel teeth are not only a breeze to install, but are also guaranteed never to leak. The faucet that’s supplied with the system is an elegant design, is lead-free, and of an exceptionally high quality standard.
When it comes down to it, we want really pure water from an RO purification system. In this regard, the APEC ROES 50 can compete with any of the best 5 stage reverse osmosis systems available today. The double carbon block filters, with larger than average surface areas, ensure that over 1000 different types of chemicals are removed from the water with a rated 99.99% of chlorine removal. I suppose there will always be that 0.01% that could slip through in any system. They claim a general “up to 99%” removal of all chemicals. Basically, the water is about as pure as you can get and as far as clean, healthy, palatable drinking water goes, it’s better than most of the bottled water that you would otherwise be buying in a store.
For a very affordable high-end under sink reverse osmosis water purifier, you’d have to search far and wide to find a better deal. You’ll always get the technical support that you need and this counts for a lot, as this RO system is going to be in your home for many years to come. APEC provide you with a 1-year limited warranty on this RO system.
2. iSpring RCC7 5 Stage
The iSpring brand is another respected name in the industry and the iSpring RCC7 5 stage reverse osmosis is a hot competitor alongside the APEC ROES 50. This is also a WQA certified RO water purifier, earning the esteemed WQA gold seal. Both the iSpring RCC7 and the APEC ROES 50 have received a 4.8 star rating on Amazon from over 4000 customer reviews. I can tell you that this is a rare and remarkable achievement. They both cost roughly the same, so it’s not easy to choose between them. Though, I’m leaning toward the iSpring as the best in this price category.
The iSpring RCC7 is designed for easy DIY installation. The push-in pipe connectors seem to be of the same high standard as those used by APEC and the faucet is also of a high quality standard. It has a 3.2-gallon pressurized tank providing 75 gallons per day (GPD) and the dimensions are almost identical to the APEC: 14.5” X 5.2” X 17.5”.
I think that the iSpring RCC7 is probably the best value for money RO system around, though this is my opinion and others may not agree. The main reason why I say this is because it’s priced very reasonably for a high-quality 5 stage RO system but it can actually be classified as a 6 stage system. They offer a 1-year money back guarantee and 3-year limited warranty, which is way better than the industry norm. The iSpring RCC7 gets a big thumbs up from me.
3. Home Master TMAFC 7 Stage
In some respects, the Home Master TMAFC could be the ultimate under sink RO system. Though if you’re going for the full package which includes a non-electric permeate pump, it’s going to become quite expensive. Then again, if you want the best of the best, you have to be prepared to pay for this.
The 7 stage reverse osmosis process used for the Home Master TMAFC is quite unique. Generally, remineralization is done as the sixth and final stage - as the water flows to the faucet.
With this RO system, there are 2 remineralization stages, the first stage is before the water enters the tank and the seventh (final) stage is the standard (after tank) remineralization stage. The reason for this is to protect the rubber bladder inside the tank. One of the biggest reasons why an RO system needs to be replaced is because of tank degradation. By adjusting the PH before the water enters the tank, the harmful effects of acidic water on the tank components is averted. So the system should outlive even the best that many other brands have to offer.
Another great and innovative feature of this reverse osmosis system are the modular filters. Generally, an RO system has a filter housing and you replace the cartridges when they’re done. This can be ahassle and, over time, leaks can develop where the housing screws into the top casing. This can result in maintenance issues as the system ages. The Home Master TMAFC utilizes all-in-one filter cartridges that include the housing – the whole filter unit is disposable. Now you may think that this is going push up your costs, these filters have to be more expensive.
But here’s the remarkable thing about these filters, they only need to be replaced after 2000 gallons. So it isn’t really that expensive and your maintenance time is reduced because you’ll hardly ever be replacing filters. These full contact remineralization filters are said to be far superior to standard filters and the catalytic carbon filters are probably the best at removing chloramines which is more stubborn than chlorine. Most RO filters are developed to effectively remove chlorine, however, chloramine is becoming the more widely used disinfectant and needs a higher level of carbon filtration.
If you go for the whole hog and pay extra for the complete RO kit which includes the non-electric permeate pump, you’ll have the added benefit of constant pressure – there’s no back pressure. In addition to this, there’s a massive water saving when it comes to the water loss through the waste water drainage. Without this pump, you’re looking at a water wastage ratio of 1:4, if you have the pump this becomes 1:1.
Naturally, this is a high-quality RO system. For the price, one would expect it to be. Like most of the best under sink reverse osmosis kits, it’s designed for easy DIY installation and it’s reasonably compact, despite the extra filtration that it provides, measuring 20 X 16 X 13 inches. It also delivers 75 GPD, which is more than the standard 50 for many other systems. It’s a US made product and carries an incredible 5-year warranty.For added peace of mind, their customer care is reputed to be excellent.
4. Express Water RO5DX 5 Stage
The Express R05DX falls into the middle of the price range, similar to the first two in this review of the best under sink reverse osmosis systems. There’s some added value in this price, you get an extra set of replacement filter cartridges with your purchase. It’s a great 5 stage RO system and is also one of the better quality systems.
I really like the steel tank. Call me old-fashioned, but I always prefer steel to plastic. If you’re concerned about the tank rusting, don’t be. Like all RO tanks, the water is isolated in a bladder that’s made of a flexible rust-free material. In this case, the bladder is made from butyl which is tough and won’t rust. Basically, the water never comes into contact with the steel outer casing of the tank. The tank is NSF certified.
This is also a very easy RO system to install and comes complete with color-coded push-in quick connect fittings and easy to follow instructions. The chrome and brass faucet is also excellent and looks great too. Filtration is exactly what you’d expect from one of the best reverse osmosis systems and you’re assured of perfectly pure drinking water with up to 99.9% removal of all harmful contaminants.
This is another product that instills great confidence, manufactured by a US company with over 27-years of experience in the reverse osmosis business. I’d place the Express R05DX up there with any of the best RO systems in this price range. People have also raved about their after-sales service and you get the bonus of an extra set of filters.
5. Global Water RO-505 5 Stage
This is another package that offers excellent value for money. Not only is the Global Water RO-505 on the cheaper end of the price scale, but you also get an additional set of filter cartridges with your purchase. It’s a very competent 5 stage reverse osmosis system that will guarantee you clean, healthy, and odorless drinking water.
While the general quality of this product is great, I have the same issue with the push-in pipe connectors as I do with some of the other budget RO systems – they’re not the best but are still of a reasonable quality standard. In all other aspects of its performance and quality, it can be ranked amongst any of the best 5 stage reverse osmosis systems.
So you have the reassurance that over 1000 harmful contaminants are removed from your drinking water with up 99% efficiency. The faucet is a really cool looking item and is top quality. It also has a steel tank which appeals to my no plastic fetish. Both the tank and faucet are NSF/ANSI 58 certified, guaranteeing your health and safety.
The complete installation kit is, like most others in this class, exceptionally easy to install and maintain. They also have a 24-hour technical helpline for US customers. It’s as compact as any of the best under sink RO systems, with dimensions of 14 X 5 X 16 inches.
The Global Water RO 505 offers an amazing combination of affordability and excellent quality. It’s as effective as anyone could want a 5 stage RO system to be and the quality standard is close to that of the more expensive systems. This all adds up to exceptional value for money.
6. HiKiNS Alkaline RO System 6 Stage
As one of the cheaper filters in this list of RO filtration systems, the HiKiNS will certainly give the Olympia OROS-50 a run for its money. This product compares very well to the other options in this review, both in terms of quality and performance.
Unlike the other filters in this list , this model comes with an alkaline filter that restores healthy natural minerals and effectively raises pH and provides pure alkaline water with a pH 7.5-8.5 . Which is nice to see on a reverse osmosis system in this price range. The components and faucet are of a really good quality standard.
Another issue with RO systems is that instructions aren’t that clear. But with this model you can see the diagrams and photographs to make things easier. It just as easy to install as any of the other RO systems. So you don't have to worry too much, if you’re not too technically minded.
The bottom line with any reverse osmosis system is the purity of your drinking water and to this end, the HiKiNS does a great job. When all is said and done, this is a very effective 6 stage RO water purification system at a fantastic price. They don’t provide any stats for the filtration, but I can’t see why these shouldn’t compare to any of the others. It seems like all the better 6 stage RO manufacturers have very similar claims in this regard – over 1000 harmful contaminants removed with up to 99% efficacy. Some of the really high-end systems boast up to 99.99%, but in this price range, one can expect the usual up to 99%. The carbon and RO membrane filters look like all the others and it should meet the general standards.
7. Brondell H2O+ Circle 4 Stage
By far the best looking of all the under sink reverse osmosis systems, the Brondell Circle is going to impress many discerning homeowners. The entire system is contained in an elegant casing, there are no filters hanging in the kitchen cabinet and it occupies way less space than any other under sink RO unit. It costs more than many others but, being one of the most efficient RO systems on the market, it will end up saving you quite a bit due to the lower water loss.
The most striking advantage of this system is its small footprint, it occupies a total area of 13.8 X 9.2 X 16.5 inches, and this includes all the filters and the tank in one contained unit.
You don’t see any filter housings and pipes running under your sink and this also means there’s no chance of bumping or snagging any of the components which could damage the system.
Without using a pump, Brondell has eliminated back pressure by use of a smart valve. This has dramatically improved the efficiency of this RO system without the need for any electrical connections or the noise of a pump. There’s virtually no water wastage. This valve has also dramatically improved the refill rate of the tank. I think this has helped them reduce the size of the tank, making the whole unit smaller. In the end, you have a really good flow rate and reduced space, an excellent and innovative design.
I’m surprised to see that this is a 4 stage system, despite being one of the more expensive under counter reverse osmosis systems. I may be wrong, but I think this might have something to do with the tank design that doesn’t require the fifth after-tank filtration stage. It’s received the WQA Gold Seal which is reserved for the best water purification systems, so it must be up there with the best of them when it comes to the purest drinking water. It also meets NSF/ANSI 42, 53, 58 and 372 standards. As far as independent verification goes, the Brondell Circle certainly ticks all the boxes.
It’s an all-around stylish unit with a remarkably elegant designer faucet. This is arguably, the most efficient RO system around and it has automatic RO filter flushing which increases the life of the filters. There are LED indicators that tell you when the filters need changing which is a handy extra feature.
I think many would fall in love with this RO system based on its looks alone. The design has the added advantage of freeing up a lot of cabinet space under your sink. Technically, it’s brilliant with really innovative design features that make it exceptionally efficient.
8. Olympia Water Systems OROS-50 5 Stage
I’m never a fan of cheap stuff, I’m always of the opinion that it’s worth paying more for the best quality. So the Olympia OROS-50 wouldn’t be my first choice when looking for an under sink RO system. Though I have to be fair here, this is not junk. If you’re not up to paying the high prices that you would for the top end reverse osmosis systems, this is one of two that I’d recommend as the best budget RO system.
I would certainly say that this is a high-quality item for its price. Above the counter, which all you see, the faucet is great quality and ranks among the best. When you go below the counter, things are slightly different.
The filter housings and tank seem to be really good quality, probably very close to the best higher priced options. My only concern would be with the quick connect push-in pipe connectors. While they’re just as easy to install as any other and are likely to remain leak-free for many years, they don’t quite meet my (rather OCD) expectations. I’ll justify this by saying most people wouldn’t be too concerned about this and if you’re paying a lower price, you couldn’t possibly expect all the components to be of the same standard as the more expensive units.
It’s a full 5 stage reverse osmosis system, so you’re getting pure water with excellent removal of particles and chemicals, by means of a 0.001 micron RO membrane – as good as any of the best reverse osmosis filters. The 50 GPD capacity is fairly standard, only a few under sink RO systems provide 75 GPD or more and all of these are considerably more expensive than this one. All the tubing and the faucet are NSF certified.
It’s just as easy to install as any of the others and occupies a space of 16” X 7” X 20”, the tank measures 12” X 12” X 18”. The installation guide is also excellent with easy to follow photographs. Though many people have said it took some time to sort out the leaks. They did, however, all manage to stop the leaking. One thing that many have repeated is how helpful the technical support team have been with sorting out any issues. That gives me a lot of confidence and negates some of my grudges with regards to this being a cheap reverse osmosis system.
If you feel faint when looking at the prices of the high-end reverse osmosis kits available, the Olympia OROS-50 will certainly come as a breath of fresh air. It’s cheap, but nowhere near nasty. In fact, the quality vs price is exceptional and they have the backup support to rival any of the high-priced “best of the best” RO filter manufacturers.
CounterTop RO Filtration Systems
If you’re renting a house or apartment, an under sink reverse osmosis system is probably out of the question. These RO units require that you drill into the counter and install a separate faucet, you also need to make modifications to the existing plumbing. Most rental lease agreements prohibit these types of modifications. What about when you go on vacation? If you’re going to rent a vacation home or own an RV, it would be beneficial to have a portable RO system that you can take with you and is quick to install and remove.
For all these situations, a counter top reverse osmosis system provides the answer. You’ll install a counter top RO unit in minutes. They have an adapter that connects to any standard faucet with a valve that you turn to redirect the water to the RO system. These are compact units that fit neatly onto any counter top and occupy minimal space. So a counter top RO system is a very practical way to have pure drinking water wherever you go. It’s quick, simple and practical.
However, there are some limitations to using a counter top reverse osmosis system. For one thing, most don’t have a storage tank and you have to switch over the water supply manually. It’s a very simple procedure to turn the valve and direct the water to the RO filters, but you have to collect and store the water when you do this. This means storing your purified drinking water in bottles and jugs. You also can’t turn on the faucet to rinse your fruit and vegetables over the sink, like you can with a permanently installed RO faucet. Some will have a storage tank with a built-in tap at the tank. Though these will obviously occupy more space and can be quite expensive.
When it comes to your routine maintenance, there’s a slight drawback in that the pre-filters used in counter top RO systems are usually smaller. This means replacing these filters more regularly.
Counter-Top Reverse Osmosis Filters
1. AquaTru Countertop RO Filter 4 Stage
The AquaTru countertop reverse osmosis unit is more versatile than most as it has a water storage tank, so you always have pure drinking water on tap. This, to my mind, is its biggest advantage.
Despite having water storage, this RO unit doesn’t take up much counter space, a really pleasant surprise. The entire thing is 14” tall, with a width of 12” and its 14” deep. It has a clean crisp design which is thoroughly modern and ergonomic. There’s a digital display that tells what’s going on with the RO filtration system.
The water storage tank fills up to about two-thirds of its capacity and then waits until it’s nearly empty before refilling, this means that the water doesn’t stand too long and I suppose it won’t collect any unwanted elements during this time. It takes about 12-15 minutes to purify a gallon of water when refilling. The 4 stage RO filtration is excellent, here are some of the official stats for the removal of harmful contaminants: chlorine – 96.6%; lead – 99.1%; chromium – 97.2%; fluoride – 93.5% and copper – 95.2%. This is pretty good but not quite the up to 99% that some others claim, though I’m more inclined to accept stats given like this than when they make the claim of “up to”. They provide a full chart of all the filtration capacity specs of this RO system on their website and on Amazon.
I like the inverted filter housing setup, it seems much easier to change the filters. Most RO systems have filter housings that hang, whereas these stand on a base. As is to be expected from a counter top reverse osmosis system, there’s virtually no installation and anyone should be able to set it up in a matter of minutes.
The AquaTru counter top RO system is a good looking compact unit that gives you pure drinking water instantly. There’s no need to fill bottles and jugs to store your drinking water. I have some concerns about plastic storage, given all the hype about BPA and BPS contamination from plastic. However, I’ve been reassured that the plastic used for this RO system’s water storage is Tritan and is deemed to be food safe, so this should alleviate any fears that you may have about this.
2. APEC Portable Countertop RO Filter 4 Stage
We’ve come to expect the best quality and performance from the APEC brand. They’re a US company and have been around for over two decades. For a high-end product, the APEC portable counter top reverse osmosis system is not at all expensive. There’s no storage tank to push up the price, so you’re getting a top of line 4 stage reverse osmosis purification without any extras.
It’s a very inconspicuous and neat looking aluminum unit, occupying a surface area of 12 X 14 inches and stands 14-inches tall. At a weight of only 10-pounds, it’s a versatile, portable item.
It fits onto an existing standard faucet in a matter of minutes and you’re ready to go. Though you should check first if it will work with the faucet that you want to use. Some designer faucets won’t accommodate the adapter and it also won’t work with spray or pull-out faucets.
It will operate fine when supplied with a water pressure of between 40 and 80 PSI to provide a very impressive 90 gallons per day of perfectly pure drinking water. Because there’s no tank, you’ll need to fill your water container at the RO unit, though this isn’t a complicated process.
For an easy to install high-end counter top reverse osmosis system, I rate this one very highly and so do just all about all of those who have bought one. Having the technical support and backing of the APEC brand is another good reason to consider this counter top reverse osmosis system.
3. Revolution Countertop Tankless Portable RO Filter 5 Stage
Despite being one of the few 5 stage counter top RO systems, the Revolution is incredibly cheap. So how can a more advanced counter top reverse osmosis system be so much cheaper? It just takes one look at the unit to see why.
It has no housing or any aesthetic features, it’s a very utilitarian looking device. You’re paying for the filters, a diverter valve,and tubing – that’s it. If you don’t mind that fact this system is downright ugly, it’s going to save you a lot of money and give you the best and purest drinking water that you can get.
The addition of a fifth deionization stage makes this RO system more advanced than any of the other counter top reverse osmosis systems. The fact that it’s just a bunch of filters connected together without any fancy enclosure makes it the most compact (7” X 14” X 7”). This makes it quite easy to conceal, which kind of makes up for the severe lack of aesthetic appeal – you can easily hide it behind a kitchen appliance. The filtration system is excellent and delivers 75 gallons per day. The stats seem to be very much in line with most RO filtration systems with some specs going as low as 85% and others as high as 99%. So the general claim of up to 99% can apply to this RO system.
If you’re not wanting to spend too much on a reverse osmosis system, this one is an absolute winner. They have in no way cut costs by using inferior components. From a technical standpoint, this is one of the best. Instead, they’ve saved by not providing anything but the basic working components. This makes a lot of sense to me. I wouldn’t mind building a simple wooden enclosure for the unit, considering how little I’d be paying for one of the best counter top reverse osmosis systems available today. This is the kind of bargain that I like.
Commercial RO Filtration Systems
Compact RO systems are great for the home, but if you’re using larger volumes of purified water, their limitations may be too great. Places like, restaurants, laboratories, hydroponic farms, and salons will require larger volumes of pure water per day than domestic RO systems can provide.
Commercial reverse osmosis systems use RO membranes that are rated for up to 5000 GPD, compared to domestic systems that range from 50 – 150 GPD. So this means that a commercial RO system can produce more purified water in a day and it will be of a similar high quality standard as the drinking water that the home RO systems provide. Generally, commercial RO systems are 3 stage, so they may not be quite as effective as household systems at removing all the impurities.
The filter housings and cartridges are larger to handle the extra volume. Those that use tanks will also have a larger storage capacity than domestic RO systems. So a commercial reverse osmosis system will obviously occupy more space. Where a tank is not used, the filters will be an in-line installation, meaning that the main water supply is connected to an inlet at the filters and an outlet pipe is led to wherever the water is needed.
Reverse Osmosis Filters for Commercial Use
1. Hydro Logic 31023 3 Stage
The best part about the Hydro Logic 31023 is its price. For a quality commercial reverse osmosis system with a reasonable flow capacity, this unit is very affordable. You’re supplied with the basics and not much more, which is what brings the price down.
The three extra-large filter housings are grouped in a triangular shape and this makes the unit very compact. Though the space-saving position of these filters makes it a little more complicated to loosen the housing when changing the cartridges.
This may not be a problem for most people, perhaps only if you have fairly large hands and they provide a plastic filter wrench to assist in making this easier. It has simple connections for the water inlet, outlet and drain pipe, with the inclusion of a pressure gauge which is nice.
The flow rate is really good at a 1000 gallons per day. It also has a really good efficiency with a waste water ratio of 2:1. Filtration is about average for a 3 stage reverse osmosis system of this size, a 95% reduction in the parts per million of dissolved solids.
For its price, the Hydro Logic offers a really good volume of RO purified water and is very a capable unit. Its compact design can also be a big advantage if you have limited space.
3. iSpring RCB3P
At an even lower price than the Hydro Logic 31023, the iSpring RCB3P is a serious contender for the best budget commercial reverse osmosis water purifier. That is if you’re not going to me using too much water – this system is limited when it comes to GPD specs.
What first impressed me is the level of quality that the iSpring RCB3P offers, especially when you look at its price. The filters are perfectly arranged in a steel frame with solid standing feet. This is in strong contrast to the basic plastic filter mounts used on the Hydro Logic RO system.
The filters and connection points are easy to access and it has a pressure gauge. If you’re using a pressurized tank this system is fully compatible, though a tank is not supplied with the unit.
Where this model falls short of its budget rival is in the lower flow rate of only 300 gallons per day. On the other hand, it has the advantage of a booster pump which increases the water pressure to optimize the osmosis filtration process and give you a steady supply of purified water. The really large 20” filters require less frequent changing, so you’ll get around 3000 gallons from a cartridge.
If your requirement for RO purified water falls within the 300 GPD that this system provides, it’s a fantastic system at an incredible price. It’s robust and offers exceptional quality, making it fantastic value for money.
The LiquaGen commercial reverse osmosis system stands out from the crowd in that utilizes a nuclear grade deionization unit that produces analytical quality water, making it one of the best reverse osmosis systems for laboratory use. The superior water quality is matched by serious commercial-grade design and build as well as a large pressurized tank.
This RO system is capable of producing up to 800 gallons of RO purified water per day, which is enough for most commercial applications. With above average filtration and a 99% contaminant removal capacity, it’s quite impressive. It’s also highly efficient with a 1:1 waste water ratio.
A digital display keeps you on top of the system functions. The entire unit is contained in a robust steel frame and every component speaks to its purposeful industrial-grade design and build.
The tank holds an impressive 40-gallons and cheaper options are available if you don’t need as much storage. This is one of the best commercial reverse osmosis systems for its size and price. A really great piece of equipment.
Complete Buying Guide on Reverse Osmosis Water Filters
Reverse Osmosis (RO) water filters are generally considered as the best way to provide clean, pure water to your home or business. Though not all RO systems are the same. Anyone who has looked into buying a reverse osmosis water purifier will know that prices and specifications differ greatly.
There are countless RO brands, each advertising the very best water purification. It’s understandable that you may feel a little bewildered by the barrage of information. With prices reaching $1000 or more for a high-end reverse osmosis water purification system, you want to have your ducks in a row before buying one. This reverse osmosis buying guide is intended to present you with the facts, so you can buy with confidence.
In order to know what you’re buying, it’s important to understand reverse osmosis. So I’ll be addressing those frequently asked questions about reverse osmosis. Here’s a basic list of what you can expect to find in our Complete Buying Guide on Reverse Osmosis Water Filters.
You may have more questions than the ones that I’ve listed. Though this is just a general overview of what this reverse osmosis buying guide is all about. You’ll be getting a lot of valuable information. In answering these questions, I’ll also be discussing RO filter stages. This is something that seems to confuse a lot of people. Some reverse osmosis systems are advertised as being 3-stage RO systems, while others claim an incredible 7-stages. If you’re wondering what this is all about, you won’t be by the time you’re done reading our buying guide on reverse osmosis water filters.
What is Reverse Osmosis and How Does it Work?
Since there are so many water filter options, let’s start with distinguishing Reverse Osmosis systems and why it works so well.
Reverse osmosis uses osmosis which is a process whereby pressure moves water through a membrane filter to remove impurities. So the main distinction between RO water purifiers and any other type, is that it uses the municipal water pressure, or a pump for low pressure water supplies, to move the water through a dense filter. The osmosis principle is then reversed to dump waste water, containing the contaminants, into the drain.
A typical RO filter consists of several layers of polymer materials, capable of particulate removal up to 0.001 microns. These membrane filters are capable of removing chemicals (like chlorine and fluoride), as well as organic matter and salts from the water.
This is not a new principle. In fact, the basis of osmosis was first discovered in the 1700s. The University of California, Los Angles (UCLA) saw the potential for RO as a method of desalination. In 1950 they began research into using RO to remove salts from sea water. By the late 1970s, many municipalities started using reverse osmosis systems to purify their bulk water supplies.
How Does a RO Filtration System Work?
A basic 3-stage RO system has a water inlet that is connected to a series of filters. Shut off valves in the system allow for water to bypass certain filtration stages when necessary.
The first stage of any reverse osmosis system, is the pre-filter. This removes larger particles that could restrict the fine membrane RO filter.
The second stage utilizes an active carbon filter which is used to remove harmful chemicals (like chlorine) that could damage the RO system.
This is followed by the RO membrane filter which removes the fine contaminants in the water. The purified water is contained in a storage tank, ready for use at any time. The tank has an outlet that can supply a single faucet, or it can be connected to the whole house water supply.
Most RO systems have a waste water drain that dispels the contaminated water from the RO filter.
This is the most basic type of reverse osmosis water purification system, referred to as a 3-stage RO system. This system could use 3 individual filter cartridges (one for each stage) or a single 3-in-1 filter cartridge. Either filter type can be just as effective.
Many RO systems have more than just the three basic stages, with some advertised as 7-stage RO systems. To clarify this, I’ll list all seven possible stages for a reverse osmosis system.
7 Stage RO Purification Process
- 1Pre-filter removes sand, silt and other particles that can block the RO system
- 2Carbon filter removes chemicals and VOCs
- 3Second Carbon filter for additional removal of chemicals and lime
- 4RO filter removes fine particles, metals and salts from the water
- 5Post storage carbon filters remove any contaminants that may have collected in the storage tank
- 6UV filter to removes bacteria from the water
- 7Remineralization replaces essential minerals lost during the filtration process and softens the water by adjusting the PH
These stages may not be exactly the same for all reverse osmosis systems. Some may use two RO filters, and only one carbon filter. The remineralization stage may not always adjust the PH to soften the water.
Do you Need a Reverse Osmosis Water Filtration System?
Most of us rely on a municipal water supply and we trust that this water is safe for drinking. The US Environmental Protection Agency (EPA) is responsible for ensuring the safety of the water supplied by municipalities. EPA regulations stipulate that all bulk water suppliers regularly test their water and make this information available to the users.
While municipal water may be deemed safe for use, many will add chemicals to disinfect the water, like chlorine. The use of Fluoride has been prohibited in some areas, but not all. So there may be chemicals in the water that can have adverse health implications. Even with regulations, there is no guarantee that the pipes delivering the water to your home are safe. In some older neighborhoods, lead pipes could still be used. Older galvanized pipes could contain rust and other contaminants that can enter the water supply in any number of ways. You can always use a test kit to determine what the water quality is at your faucet.
Private wells are not subject to any type of regulation. If your water is supplied from a well, you will not know what is in your water, unless you have it tested. Private laboratories or the CDC will test your private water supply for you.
Apart from the obvious health concerns, contaminants in the water can lead to blockages in your water pipes and may damage some appliances like water heaters, washing machines, and dishwashers.
In most cases it is preferable to filter the water that you drink, use for bathing, or general cleaning. A water filter pitcher is probably the cheapest way to ensure that your drinking water is safe. Though they are not the best.
Water purification pitchers seldom offer a high level of filtration. They are also inconvenient, in that they hold a limited amount of water. When you refill the water pitcher, it takes a long time for the water to trickle through the filter. This is not ideal for a busy home where a lot of water is used. They are only suitable for drinking water and can’t supply your shower, bathtub, or washing machine.
Depending on the type of filters, and how many stages it uses, a reverse osmosis water filtration system will offer the following benefits:
In the end, reverse osmosis water filters are considered to be the best method of supplying pure, healthy water to your home.
Which Reverse Osmosis System Should You Buy?
Before buying a reverse osmosis system, you should assess your needs and, of course, your budget. When it comes to price, there could be a need to compromise. You may not be able to afford the ideal RO system for your home. Though, by understanding what is important, you’ll know how to maximize your dollar when buying an RO system.
I’ve listed the stages of reverse osmosis, and this will affect the price. While multiple stages are great, you will usually pay more for reverse osmosis systems with more than three stages. If your budget is limited, rather opt for good quality 3-stage RO filter. If a 7-stage RO system seems to be unbelievably cheap, you have to ask yourself why. In my experience, the price you pay is always related to the general quality of the product.
It is all about what type of RO system is going to meet both your needs and budget. You also need to look at how the RO system is installed. Some reverse osmosis systems are easy to install and remove. If you are renting, or don’t intend staying at the same place for too long, you want an RO system that doesn’t require any changes to the existing infrastructure.
A whole house RO system is connected to the main water supply and will require changes to the plumbing in your home. Once installed, these RO systems are not easily removed. You should view these systems as a permanent installation.
Under sink reverse osmosis systems are aesthetically pleasing, in that the filters and tank are installed inside a cabinet and hidden from sight. Though these systems may require drilling through a countertop and will require a certain amount of alteration to the existing plumbing.
Above counter RO filters are often the easiest to install. Some will come complete with universal kits that allow them to be connected directly to a faucet. This means no drilling or cutting. They can be removed easily and are generally quite portable. This may have some restrictions, like a smaller water tank or no water tank at all. This may result in a restricted water flow with lower pressure. Though, in most cases, this will not be an inconvenience. It will depend on the water pressure supplied to your home.
Take a good look at the filters. Some are really easy to remove and refit. You will be changing your filters fairly regularly. So, filters that are easier to remove and refit, will be much more convenient. The price of the filters, and the expected lifespan, is also important. The best way to determine what your RO system is going to cost to run, would be to read reverse osmosis reviews on a trusted review site. A filter that is more expensive, but lasts longer, may be cheaper in the long run. It’s also a lot less hassle if you only need to change your filters once a year, instead of every three months. A warning light that notifies you when to change the filters is nice to have.
How much water is wasted can be an important factor, especially if you’re paying high water bills. Some RO systems use a lot of water to flush the system after every use. Others waste little or no water during the reverse osmosis process.
If you have low water pressure, like well water supplied form a gravity fed tank, you’ll probably need a reverse osmosis system with a booster pump. These pumps will increase the water pressure every time the RO system is used. One consideration, is that these pumps can be quite noisy. Many under sink RO systems, with a booster pump, are designed not to cause an inconvenience. This means using a booster pump that is relatively quiet.
RO systems can have no controls, some can be quite advanced. An automatic maintenance cycle can be a great advantage. Most RO systems will need to be completely flushed with clean water periodically. This keeps the tank and pipes in good condition and removes unwanted impurities that can collect in the system. Some will do this automatically, others will require you to run a maintenance cycle when required. Generally, RO systems that don’t have an automated system, will have a warning light to inform you when you should run this maintenance cycle.
Advanced reverse osmosis systems, that adjust the water PH, can have a number of settings for the alkaline quality of the water. The way this is done, can be quite confusing. Easy to follow PH guides on a touch panel are great. They allow you to adjust the perfect PH for varying applications, like washing, tea or coffee, cooking, and drinking. As one would expect, advanced electronic controls will be reserved for the more expensive reverse osmosis systems.
How to Install a Reverse Osmosis System
When considering the installation of an RO system, there are three types, with varying levels of installation ease:
There is no universal guide to installing a reverse osmosis system, so you will always need to consult the instruction manual for detailed instructions. Most RO kits are designed for easy DIY installation. Push lock fittings with color coding make things much easier.
I’ll provide some installation tips for each type of RO system.
Installing a Whole House Reverse Osmosis System
Finding the best place to install your whole house RO system is important. It needs to be connected to the main water supply to your home. This means that you will need to redirect the pipe that supplies your home through the RO system.
While you want the most convenient position for your whole house filtration system, with the least amount of extra plumbing, your system needs to be protected and you want easy access to the filters. A sheltered position, that doesn’t receive any direct sun is going to protect your RO system and prevent it from deterioration over time. If your RO system requires an electrical connection, it needs be sheltered from direct exposure to rain or snow. A garage is often the ideal place for an RO system if it is close enough to the main water supply.
Before you install the system, calculate the pipes and fittings that you will need and make sure you have everything. You will need to shut off the main water supply before installing the RO system. So you don’t want to find out, once you’ve started, that you need to rush off to the hardware store for additional fixtures. You should do as much drilling and mounting as possible before you shut off the water supply. This will minimize downtime in your home when there is no water.Mount your filters in a position that is easy to access. You’ll appreciate this later when you need to replace the filters. Follow your instructions closely and install the pipes as recommended by the manufacturer.
Installing an Under Sink Reverse Osmosis System
Under sink RO systems require the most planning because the space inside an under sink cabinet is limited. These systems usually have easy to follow instructions and kits to make it easier to install and understand. So the most important part is pre-planning your installation.
Take note of where you mount the filters, you want these to be of least obstruction in the cabinet, but easy to access when the filters need replacing. To one side of the cabinet, close to the door opening is usually the best position for the filters. The tank is usually quite large and you will probably want to install it at the back of the cabinet, out of the way. You won’t need to perform regular maintenance on the tank, so access to it is not that important.
When installing the PVC pipes that are supplied with the RO kit, make sure you keep them out of the way. Pipes that are obstructing normal use of the cabinet can be easily snagged and damaged. Follow the manufacturer’s instructions throughout the process.
Installing an Above Counter Reverse Osmosis System
There is no real complications to installing an above counter RO system. You may have to drill holes for the filter rail, but this should be all the DIY skills need. You should have an adapter that directs water from the faucet to the RO system and a return pipe to the faucet.
These systems may vary slightly, but the instruction manual should give a clear guide to the installation process.
Maintaining a Reverse Osmosis System
Basic maintenance of an RO system is quite simple. You need to replace your filters as directed. This can be anything from three months to a year. It will depend on the amount of water that you use and the type of filter.
If your RO system requires that you run a maintenance flush cycle, you will need to do this in accordance with the manufacturer’s guidelines.
Long term maintenance will entail replacing seals and plastic fittings. Though most quality RO systems will function perfectly for many years before this becomes necessary.
How Much Does a Reverse Osmosis System Cost?
A reverse osmosis system can cost as little as $120 (perhaps even less), while others can reach well over $1,000. If we’re talking about a whole house RO system, installed by a professional, you’ll be looking at paying over a grand for a high-end system.
On the cheap end of the price range, (under $200), you can get some great quality reverse osmosis filters. These will usually be 3-stage RO systems. Some have a faucet included in the kit and this will cost extra. If you’re wanting to spend $120 - $150 on an RO system, choose one that does not include a faucet. At this price, you will get an inferior faucet and the filter cartridges, as well as the pipes and fitting, are also likely to be second best. At the low end of the price spectrum, keep things basic.
The size of the RO system has a big impact on the price. Some reverse osmosis filters have 70-gallon tanks or bigger. These systems are not only bulky, they’re going to cost more. While it’s a good idea to match the gallon capacity to your needs, know that you’ll be paying more for a larger system.
Additional stages, especially UV filtration and remineralization, will be more expensive. Automation and fancy electronics also come at cost.
When considering your reverse osmosis costs, look carefully at how much the filters cost and how long they last. When you buy your reverse osmosis system, it’s a once off expense. Your filter cost is going to affect your budget for years to come. Sometimes, spending a few dollars more today, can save a lot more over time.