Express Water RO5DX 5 Stage Reverse Osmosis Filter Review

Express Water RO5DX 5 Stage Reverse Osmosis Filter



If you are looking for a budget RO system for your home, the Express Water RO5DX 5-stage RO water purifier is one of the most affordable in the market.

The lower price tag doesn’t reflect its filtration performance. The 5-stage filtration process removes just as many impurities as other premium RO systems.

It even comes with four spare replacement filters.

What you’ll sacrifice is a couple of extras that are not very essential to filtration. These include a remineralization filter and a permeate pump.

The daily production capacity is also lower than that of most RO filters, but it still filters more than enough water for most families.

Overall, you won’t get a better RO system for the price.

Learn more about the Express Water 5-stage RO filter in our full review below.

If you are looking for a premium RO system with more features such as an alkaline filter or an integrated pump, read our in-depth reverse osmosis water filters buying guide for the best recommendations.



Product Specifications


Filtration System Design

Express water 5 stage filtration

The Express Water RO5DX is a barebone RO system with just the basics it needs to purify the water.

So you don’t get a remineralization filter or any other extras. Just 5 filters that remove hundreds of impurities from your drinking water.

The filters are arranged the same way as in other RO systems: pre-filters first, the RO membrane in the middle and the post-filter at the end.

Here’s what each filter does.


The water goes through the pre-filters first, where sediment and organic chemicals are filtered out of the water.

This makes the water cleaner and safer to drink and protects the sensitive RO membrane from damage and clogging.

The pre-filters, and specifically the two carbon pre-filters, play an especially important role in removing chlorine from the water.

Chlorine can damage the RO membrane, reducing its ability to reject impurities. This allows more contaminants to pass through the membrane, which compromises water quality.

That’s why it’s also important to replace the pre-filters on time before they degrade to a point where they allow some chlorine through.

The first pre-filter is a standard sediment filter.

It removes large particles suspended in water such as silt, dust, rust, and sand. This reduces water turbidity and ensures the sediment doesn’t clog the carbon filters.

The next two pre-filters are both carbon filters, though different types of carbon.

The first is a GAC or granular activated carbon filter. It consists of loose granules of activated carbon that adsorb chemicals like chlorine and pesticides from the water.

The second is a carbon block filter. It’s still made from activated carbon, but the carbon particulates are compacted into a block.

Because of its design, the carbon block filter has a bigger surface area for water to interact with.

This improves its ability to adsorb chemicals like chloramines, herbicides, and other organic substances from the water.

Combined, the two carbon filters remove almost all chemicals that affect the taste and smell of the water. They also remove harmful chemicals.

Reverse Osmosis Membrane

The RO membrane at the heart of the system deals with the hardest-to-remove contaminants.

This mostly includes TDS (total dissolved solids) and biologicals.

TDS include all inorganic minerals and salts dissolved in water such as nitrates, heavy metals, arsenic, hardness minerals, and fluoride.

Biologicals include pathogens such as bacteria, viruses, and cysts that can cause waterborne diseases.

From the RO membrane, the water goes into the 4-gallon reserve tank.


In the reserve tank, the water can pick up some unpleasant odors, and tastes from the rubber tank bladder.

A final polishing filter gets rid of them, ensuring the water tastes and smells fresh.

The final filter is an in-line activated carbon filter that you need to replace every year.

Filtering Performance

RO filter

The 5-stage filtration process does a pretty good job, comparable to any other RO system.

The Express Water RO system does not compromise on performance for the lower price tag.

The removal rate, which is 98% or more for most contaminants, for the five filters is similar to that of other more expensive RO systems.

The purified water looks incredibly clear, tastes fresh, and has ultra-low levels of TDS (you can test it yourself using a TDS meter).

Where the Express Water filter compromises are in flow rate and production capacity.

Since it doesn’t come with a permeate or booster pump, the flow rate is on the lower side. It might take a while to fill a 5-gallon water bottle.

The problem will be worse if your home’s water pressure is already low.

But you can easily solve this by adding your pump to increase water pressure.

As for the production capacity, the Express Water system can filter up to 50 gallons per day. That’s lower than the 75 GPD capacity of most RO filters.

But 50 gallons is still plenty of drinking water for most families.


Express Water RO5DX

This is another area where the Express Water RO5DX lags behind other premium RO filters.

It has a water efficiency ratio of 3:1, which means it drains 3 gallons for every gallon of purified water. This is quite wasteful compared to RO systems that waste just 1 gallon for every 1 gallon of purified water.

The main reason for the low efficiency is the lack of a permeate pump.

permeate pump reduces wastage by increasing the pressure of water as it goes through the filters. When the water has a higher pressure, more of it gets into the tank, and less gets directed down the drain.

Thankfully, this is a problem you can improve by installing your permeate pump. An electric booster pump can also work.

Alternatively, find a way to get the drain water and use it elsewhere such as gardening.

Chemicals that are potentially harmful to plants are left behind in the carbon filters. So the water is generally safe. Most plants don’t mind high-TDS water.

Installation and Maintenance

reverse osmosis system reviews


If you’ve ever installed an RO system before, the process is pretty much the same with the Express Water filter.

If this is your first RO system, don’t worry, it’s a straightforward DIY job. It takes about an hour or two to get everything set up.

The instructions are clear, and you can even get some helpful installation videos online.

To make installation easier, the system uses a color-matching system.

The red tube connects to the red connector, the black tube to the black connector, and so on. It’s impossible to get it wrong.

Like most systems, the Express Water RO5DX uses push-to-connect fittings. You don’t need any tools to connect the tubes.

The only part you’ll need a tool is when you are drilling a hole in the sink for the faucet and another in the drainpipe for the drain line.

But check your sink first to see if there is a spare hole you can use.


One of the reasons the Express Water RO5DX is cheaper than most RO systems is that it uses lower quality filters. They are not low quality in that they do a worse job filtering impurities. Rather, they last for less time than other filters. While standard filters in most RO systems can last up to a year, you need to replace the Express Water filters every six months. The RO membrane lasts just one year, while most can last up to 3 years. The reduced filter lifespan does mean you have to spend a bit more time under the sink changing out the filters. But it doesn’t significantly increase maintenance costs. That’s because the replacement filters are cheap. The system comes with four spare filters for the first replacement. For future replacements, get the extremely well priced 3-year filter pack consists of 23 replacement filters and RO membranes.

What We Like the Most About the Express Water 5-Stage RO System

Express water undersink water filter

What We Don’t Like

Clean filtered water

The Express Water RO5DX Is Perfect For You If...

Express Water alkaline RO System

You are looking for a budget reverse osmosis filter that is reliable, easy to install, and maintain, and is effective at filtering out impurities.

Our Bottom Line

Express Water RO5DX 5 Stage Reverse Osmosis Filter

It’s great to see RO systems getting cheaper. It allows more people to enjoy the benefits of drinking purified water.

The Express Water RO5DX is affordable without compromising filtration performance. Even the replacement filters are pocket-friendly.

You won’t get a better deal at this price.

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