RO5DX Reverse Osmosis Water Filter Review

By bill_r / February 1, 2017

5 Stage Home Drinking Reverse Osmosis System (RO5DX) Review

Water is definitely an important part of our life. But, more importantly, we don’t want water with toxins in it. The water that we get naturally in the environment has picked up impurities like fluorides, chlorine, dust and sand particles and other undesirable minerals in it. Thus, it’s important to purify or filter the water that we consume.

As a result of this demand for clean water, there have been many companies that have sprung up with water filter products using their own innovative technologies to do so. One such company is Express Water, and it has been pretty successful at this! Express Water is one of the premium manufacturers of water filtration systems. Regularly ranked as best in the business, they have been in operation for more than 25 years and that speaks volumes about their achievements in the industry. Going further, not only are they top ranked in the US, but they are also recognized globally as one the best companies when it comes to water filtration systems.

Their products come with a one-year warranty and have an easy-to-read instruction manual. They value and help their customers as shown by the fact that they remind their customers to replace their filters once every year.

Today, we shall be reviewing one of their products, the 5 Stage Home Drinking Reverse Osmosis System (RO5DX) which was featured as one of our picks for the best reverse osmosis water filters and wins our award for Best Value!

Criteria for a good RO filter

Before we review the features of the Reverse Osmosis System, let's understand what the process of reverse osmosis is and how it helps purify the water. Reverse osmosis is one of the many ways to filter impurities from water. However, it is the most widely used and preferred method because it’s cheap and effective. The resulting water has good taste because it’s free from impurities.

Overview of a Reverse Osmosis Filter​

The process is carried out in 4-5 steps (depending on the design), and water to be treated is pumped through sediment and carbon filters which remove the chlorine, sand and dust particles and larger contaminants. The water then flows through the semi-permeable reverse osmosis membrane after which the filtered water is stored under pressure in a small storage tank. The final stage usually consists of another carbon filter, which is basically a post-filter before the water is made available for our consumption. A more detailed explanation can be found on our How Does Reverse Osmosis Work with a helpful infographic for showing the process.

Every reverse osmosis filter has the above mentioned components, but the effectiveness of all the components determines what makes a filter better or worse than other filters. First, the pumping mechanism used must be able to deliver water at the pressure necessary for efficient operation. Secondly, it is very important that filters used are of good quality and perform their function efficiently, have a long life and require as little maintenance as possible. While removing the contaminants, some water filters also filter out some nutrients and minerals that have a pleasing taste.

Now that we have an understanding of the process, and the stages involved, let’s go over the features of the Express water reverse osmosis filter to see if it meets the criteria for a good filter.

RO5DX Water FilterFeatures

To start off, with dimensions of 16.2 x 18.8 x 18.1 inches and weighing 30 pounds, the filter is similar in size and weight to its other competitors. The RO5DX also has a huge 4.4 gallon storage tank, which is slightly bigger than the competitors. It also has a flow restrictor to regulate the pressure of water pumped to the membrane to the range of 45-75 psi. It can modulate the pressure to give optimum results. The reverse osmosis filter utilizes 5 stages in the filtration process. Let’s have a look at each stage,

  • Stage 1: As the water is flows through the filter, it first passes through a 5-micron melt-blown polypropylene sediment filter which is responsible for removing the initial large and fine particles in the water. These particles include sand, silt, dirt and rust particles which spoil the taste of water if not removed. They can also cause clogging of the subsequent membranes if not removed, and thus this filter is very important in maintaining a long life of the membrane.
  • Stage 2: Granular Activated Carbon (GAC) filters are used in this stage, to remove chlorine, odors, and also the numerous organic compounds.
  • Stage 3: Another carbon filter is used in this stage. This time a 5-micron fine coconut shell carbon filter is used to get rid of the remaining chlorine, odors, taste, and other chemicals.
  • Stage 4: This stage is considered the heart of the water purifier, the thin film membrane, where reverse osmosis takes place. Water passing through here is 99% free of bacteria, viruses and chemicals in it, making this a very critical stage in the entire process.
  • Stage 5: The final stage of the process consists of Inline Granular Carbon filters, where the last few remaining traces of any of the odors and tastes are removed.

Pros & Cons

The RO5DX has quite a lot of advantages, but it also has some cons against it. Let’s take a look at the pros and cons,


  • The filter does not require electricity to operate.
  • The most important thing of any device is that it should be easy to assemble and install. The Express water filter comes with an easy to understand instruction manual, which makes the installation process easy and fast.
  • It has a valve to automatically shut it off when the tank fills to two-third its capacity, so there is no danger of overflow from storage tank.
  • It has extra filters included free of cost.
  • Excellent customer service ensures prompt response if troubleshooting is required.
  • 5 Stage Water Filter.
  • Great price. Great value for the money.


  • The 1/2-inch slip joint adapter included is not particularly useful, and it would be better to include a 3/8-inch adapter instead. This means an adapter may be needed during the installation.
  • 5 stages means more filters to change/replace.


The Express water RO water purifier is without a doubt an amazing device for a very reasonable price. Consisting of five stages, it extensively removes the impurities found in untreated water such as dust, sand, silt, fluorides, chlorides and other harmful chemicals to give us safe, clean and odorless water.

It’s easy to install, use, and comes with excellent customer service. Although we're disappointed with the incompatible adapter, this isn't too much of a concern and in no way hampers the function of the water filter. So, in conclusion, with all these advantages, great features, and costing less than two hundred bucks, it definitely wins our best value designation.

About the author


Hi and welcome to my website. I'm Bill Robertson and I worked my way through school as a handyman. The skills I learned have been useful as I've made changes to my own home. As a father of a 3 children, having a healthy water supply is important. Because the Central Texas well water was so hard, a water softener and reverse osmosis filter were critical. The water softening process was interesting and resulted in such a difference in water quality that I wanted to know why. This website is the result. Central Texas is famous for its hard water and I likes sharing what I learn experience with other readers.

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