We will lead the way by talking about some of the finest products you can locate out there. Our experts have decided to share a few words of wisdom with you pointing out the strengths and the drawbacks of 10 of the nicest RO filtration systems you can buy. Check the list out and keep in mind that we have assembled it in no particular order.

Reverse Osmosis Membrane
Best options for Domestic water RO membranes under sink ro system, 50 GPD, 75 GPD, and up to 400 GPD ro membrane are available in different USA & Taiwan Brands
HOW WILL A REVERSE OSMOSIS SYSTEM HELP US?
Needless to say, municipal water supplies typically provide you with water containing a huge number of contaminants. In fact, the easiest way to see the difference between processed and raw water is to use a TDS meter. This is the main tool that will convince us that a reverse osmosis system is a must for almost any household.
BENEFITS OF USING A REVERSE OSMOSIS SYSTEM
What we shared above should be more than enough to convince you that you can’t just put up with tap water, However, we will dive into listing a few more benefits related to operating a reverse osmosis system. So here’s what we got in no particular order.
- Who Needs Bottled Water Anymore?
People who look to have tasty water often fall for buying bottled water from the store. While this sounds like a very healthy idea, it actually isn’t. Those bottles are plastic and this can lead to a number of health hazards for regular users. If you want to consume water from a bottle, you ought to go for glass and never plastic.
- Solves the “too much sodium” problem with softened water
It is only normal for families to want to have softened water at home. This is achieved by getting a reliable and trustworthy water softener but other issues will still remain. For instance, softened water always contains high levels of sodium thanks to the resin located in the tank. This renders the water good for washing and cleaning but definitely not very tasty for drinking and cooking.
- Takes cooking to a new level
It doesn’t come down to just taste. Municipal water typically contains high amounts of chlorine. When you bake bread or boil soup, this might even lead to some unwanted color changes of your food.
Additionally, there might be some sort of odor you will likely want to get rid of. Regardless of your reverse osmosis system cost, it will definitely take care of this aspect for you. Even the simplest RO systems will allow you to have odorless and colorless water for cooking. Many people prefer using a water distiller in order to get water for cooking. This indeed is an option but you lose the opportunity to actually add some useful substances to your water or alkalinize it.
HOW DO RO SYSTEMS WORK
Simply looking at under sink reverse osmosis water filter reviews is not going to be enough to understand and appreciate the functionality of the device. This is why in this section we are going to focus on the process called reverse osmosis as well as the components of the system, and how they perform together.
THE PROCESS OF THOROUGH PURIFICATION
In short, reverse osmosis works by forcing water through a specialized plastic membrane sheet. This way a number of compounds such as organic substances, salts, viruses, and microorganisms are removed from the water. We can also include pharmaceuticals in the list.
You might have noticed that the cartridges are typically cylinder-shaped. This is because the membrane sheets are wound into such a shape. But each of these long pressure vessels houses a number of elements inside itself.
So water flows through the “cylinder” where all those sheets are rolled up and then exits it. The membrane layer is exceptionally thin. It allows water to pass through, a process also known as permeation, while other compounds are blocked.
Thus molecules are removed based on their size, shape, and charge. This means that 99% of the time, molecules larger than those of water cannot pass through. This, of course, includes a wide array of chemical contaminants and microorganisms.
Two streams of water are therefore produced. Pure clean water, also known as “permeate”, gets across the membrane sheets and enters the inside core tube. This is the water that you are to use. Water that doesn’t permeate is concentrated with contaminants and salts and is usually called “concentrate water” Needless to say, this water leaves the system through the drain and not the clean inlet pipe leading to your faucet.
THE STAGES OF A USUAL REVERSE OSMOSIS SYSTEM
For the sake of covering as many aspects as possible, we will describe what happens when a relatively thorough domestic RO system is used. Keep in mind that some components and parts of the stages are optional and will not be available with all the systems you can buy. Refer to our individual best reverse osmosis system consumer reports for more detail. Some of the core stages, however, include:
- Filtration stage
- Reverse osmosis stage
- Alkalization stage
As soon as the water enters the system, a sediment filter (typically of 5 microns) retains suspended particles such as algae, dust, sand, and many others.
In the next phase, there is an activated pre-carbon filter. It traps minerals and contaminants some of which are chlorine, PCBs, pesticides, and organic compounds. Now comes the carbon filter in the 3rd stage which further neutralizes chloramine in order to make it easier for the RO membrane in the next phase. It is quite obvious that you do not necessarily require all 3 filter cartridges and most cheap reverse osmosis systems will not have them.
At the beginning of the 4th stage, we have clean water but definitely not pure. This is where the actual reverse osmosis happens. Its membrane will remove about 99% of all undesirable items. They include:
- Nitrates
- Impurities
- Bacteria
We move on to the 5th stage where odor, germs, bad taste, and dyestuff are all removed from the water. This is a polishing filter with activated carbon. In order for it to be used, the manufacturer has to make sure that this cartridge clears all NSF regulations.
The 6th stage really shines there. The water passes through a canister of a natural organic material which will mineralize and revitalize it. Magnesium, calcium, and potassium come to mind. Such stones are a rarity and they come at a price. When combined with osmosis water, the water molecules increase the amount of oxygen in your water. NOTE: Be aware that a water softener removes magnesium from water and adds sodium to it. What you want to do is have the softener connected before the RO system.
The 7th and last phase is the one with the alkaline filter. It will reduce the acidity of the water and will increase the pH levels. If you can cover all those stages with your home RO system, then you will truly have the purest water possible.
6 Stages 50 GPD EVO Pure RO System W/ Plastic Body
6 Stages 50 GPD EVO Pure RO System W/ Plastic BodyThe EVO PURE Reverse osmosis Systems with Booster Pumps are traditional in design with Good Quality filter housings and a pressure tank.
Alkaline RO 8 Stages 75 GPD System
Alkaline RO 8 Stages 75 GPD SystemIncrease the pH of the filtered water typically to between 8.5 to 9.5. Changing the oxidation/ reduction potential of the water (ORP) to between -100mV and -250mV.
Non-electric 1000 GPD Reverse Osmosis System
Non-electric 1000 GPD Reverse Osmosis System4 Stage Electric Free Direct Flow RO Water purifier is specially designed to work without Electricity and on normal pressure of tap water (0.3Mpa). The compact and small size makes this System Special.
Ultraviolet 7 stages 75 GPD RO System
Ultraviolet 7 stages 75 GPD RO SystemSystem provides your family with premium water for drinking and cooking at a fraction of the cost of bottled water. That means no more deliveries, heavy containers, storage problems, spills, or bottle deposits.
Ultratec 75 GPD RO System
Ultratec 75 GPD RO SystemSystem provides your family with premium water for drinking and cooking at a fraction of the cost of bottled water. That means no more deliveries, heavy containers, storage problems, spills, or bottle deposits.
SOME IMPORTANT QUESTIONS ABOUT REVERSE OSMOSIS DEVICES
Before we dive into the topic of how to select your RO system, we will conduct a short Q&A session addressing some key questions. They will help you also figure out some main reverse osmosis pros and cons and will aid you with coming up with a good setting.
- Does my Faucet Matter?
Not only that it matters, but you will also actually need a separate one. RO systems give you excellent drinking and cooking water but it is not suitable for washing. Activities that require larger amounts of water are typically carried out using another faucet.
Hot water also doesn’t go through reverse osmosis systems. This fact also disqualifies washing dishes from the equation. Additionally, the water pressure and the GPM of your RO faucet are not going to be huge. Because of the little amount of purified water and the low flow speed, you must always use a separate faucet.
The type of RO faucet is also important. Knowing the difference between “Air Gap” and “Non-Air Gap” faucets will prove to be useful in this case. Having an air gap can be quite useful as it will prevent drain water from entering the RO system again. On the other hand, you will find the non-air gap faucets to be easier to install.
- Will my water be softer?
No, it will not be. If you have hardness levels of 7 grains per gallon or more, then your water can be rendered hard. Reverse osmosis systems will not remove any magnesium from your water which is the main source of hardness.
You can hook up a water softener but you need to bear in mind that this is a whole separate system and it will come at a price. The RO device must always be connected after the softener in order to reduce the levels of sodium which will significantly rise during the softening process.
- Can I pair my RO system with other filters?
You can absolutely do that. In fact, most reverse osmosis systems come with a few cartridges. You can opt to get a full-blown complete house water filter but an RO system will pretty much have the same effect.
Most such devices come with cartridges with activated carbon. They will “prepare” your water before it gets to the membrane of the RO system. More advanced water filtration is always a great idea. Go for it.
- So how many stages of filtration are enough?
Typically 4-5 stages are just right. Refer to our section depicting the stages of a usual reverse osmosis system above. This is especially important when you have well water. In this case, go for as many pre-filtration stages as you can.
- What amount of cleansed water will I get every day?
The GPD (Gallons per day) values vary from model to model. While the manufacturer will likely list a certain amount, you can expect to get about 75% of that rating. An example of a usual GPD rating is 50. Barely any household will use 50 gallons of water daily.
Such a system is more than enough for a family of 4. As far as water pressure goes – 60 PSI is the realistic number here. As mentioned above, water flow speed is not among the main strengths of reverse osmosis systems.
- Is any water wasted?
When your RO system performs its functions i.e when it processes water, some water is definitely wasted. In fact, you will lose pretty much just as much water as you cleanse. The good thing is that once the tank is full, no more water goes down the drain.
Water is required for the membrane to clean itself but the system automatically shuts down when it is not needed anymore.
REVERSE OSMOSIS SYSTEM INSTALLATION
It is clear what this section is about. Without any further ado, we will move right to the process itself. While it is not rocket science, installing a reverse osmosis system properly can be tough if you have little or no experience. Consult a professional if needed.
- This pre-filter phase is very similar in its nature to install pretty much any type of water filtration system. Each filter element has a designated location. There are typically 3 cartridges. Use the wrench to tighten them up.
- Next comes the membrane. This is an actual reverse osmosis component and it is perhaps the most important one. The tank of the membrane usually rests on top of the casing with the filters. As you remove the black caps from both ends of the membrane, install it inside the housing. It will snap right in.
- Quick Connect fittings are what you will likely have with your RO system. Remove the clip and squeeze the tube, make the connection and then install the locking clip again.
- Turn off your cold water supply and make sure your faucet is completely drained of any remaining water.
- It is best if you use a Stop Valve. Remove the cold water flex line and put the valve there. Then put the flex line back. Soft connections are recommended here. Then simply connect the red tubing into the adapter.
- Installing your faucet will require for you to drill a hole at a desired location on the sink. Once you have installed all the fittings and rubber seals, install the faucet into the hole.
- As you go under the sink, place the nut and the collar onto the blue tubing. Connect it to the bottom end of the faucet and tighten it.
- The tank shut-off valve is also connected easily using the yellow tubing and the quick connect fittings. Again, just use the blue clips.
- The drain saddle can be installed anywhere on the drain pipe. Drill a 1/4 –inch hole in the drain pipe and install the sticky foam pad right on the hole. Install the back plate and the bracket. As you put the black nut on the black tubing, connect the tube to the drain pipe and tighten the nut.
- Follow the colors of the tubes and connect them to the respective holes on your RO system.
- Start the cold water supply again and check for leaks. Let the tank fill and after 2 hours have passed, drain it completely. This is called flushing and it must be done before using the device for the first time.