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Express Water RO5DX 5 Stage Reverse Osmosis Filter Review

The Express Water RO5DX 5-stage reverse osmosis system is a great choice for those who are looking for a budget RO system.

Despite the lower price tag, it performs just as well as some pricier RO systems. The only thing lacking is a remineralization stage.

Its daily production capacity is also on the lower end (50GPD), but it’s still good enough for most families.

The flow rate is quite good, unlike most RO systems that produce only a trickle of purified water.

The system is easy to install with color coded tubes and quick connect fittings making the process a breeze.

Read on for our full review of the Express Water RO5DX reverse osmosis filtration system.

If it’s not what you are looking for, read our reviews of the 12 best reverse osmosis water filters for other recommendations.


  • Very affordable
  • Easy to install and maintain
  • Good water flow rate
  • High filtration performance – remove over 99% of various contaminants
  • Includes a leak protector


  • RO membrane has a short lifespan
  • Relatively low daily production capacity

Product Specifications 


  • Number of stages: five
  • Production Capacity: 50 gallons per day (GPD)
  • Wastewater to pure water ratio: 3:1
  • Reserve tank capacity: 3.2 gallons
  • Booster pump: no
  • Remineralization stage: no
  • Filter lifespan: 6 months
  • Membrane lifespan: 1 year
  • Installation kit: yes

Best Features 

diy reverse osmosis

1. 5-Stage Filtration System

Here are the five filtration stages.

Sediment filter: Removes suspended particulates including dust, sand, rust, and sediment. The sediment filter clears up water turbidity and prevents the carbon filters and RO membrane from clogging.

Carbon block and granular carbon filters: These two filters focus on getting rid of any unusual tastes and smells in the water. They filter out chemicals like chlorine, fluoride, hydrogen sulfide, VOCs and pesticides.

RO membrane: Removes most of the other remaining contaminants including lead, arsenic, total dissolved solids, and fluoride. It also captures waterborne microbes including bacteria, cysts, and viruses.

Activated post carbon filter: Gives water a final polish before it comes out of the faucet. This removes any remaining smells and tastes (some of which form when the water sits in the reserve tanks for too long).

2. High Filtration performance

The five filters above do a great job removing most of the contaminants and impurities in water.

Whether you receive well water or city water, the system provides clean and safe drinking water.

Because the Express Water RO5DX doesn’t have a remineralization stage, the water may not tastes as springy as bottled mineral water.

But most customers don’t notice the difference with the bottled water they are used to. The carbon filters ensure the water tastes fresh.

3. Average Production Capacity and High Flow Rate

Production capacity for the Express Water RO5DX RO system is not the highest in the industry. Under optimal conditions, it can produce up to 50 gallons of water per day.

But 50 GPD is still plenty of water for most families. If you only use the purified water for drinking, the Express Water RO5DX system will meet your needs.

Unlike most RO systems, the Express Water RO5DX produces water at a decent flow rate of about 0.8 gallons per minute.

It takes just a few minutes to fill a water bottle or pitcher.

4. Leak Protection

Leaking is common with water filtration systems, especially those hidden out of sight under the sink or in the basement. It mostly occurs around joints and connections.

Some plumbers tape or lubricant should fix the problem.

But you need to discover the problem in the first place. If you don’t regularly check the filter, it might keep leaking for days, flooding the floor under the sink and causing damage.

The Express Water RO5DX has a way to ensure nothing like that ever happens.

It comes with a leak stop valve that automatically cuts off the water supply to the filtration system if it detects moisture on the floor.

This is especially helpful if you spend most of your time away from home. It gives you peace of mind that you won’t come to a flooded kitchen.

Installation and Maintenance 

Installing the Express Water RO5DX is a straightforward process. They’ve made it as easy as possible for anyone to install it with basic tools.

The system comes 50% pre-assembled. You only need to fit the tubes and a few other parts. The tubes are color-coded, so it’s easy to know where each goes.

By the way, you don’t have to mount the system on the wall under your sink. You can just leave the filters freestanding on the floor next to the reserve tank.

You don’t even have to install it under the sink if you don’t have enough space. You can install it anywhere there is a cold water line and a drain line.

Just make sure there is adequate water pressure. Otherwise, the flow rate out of the faucet will be frustratingly low.

If your tap water is already at low pressure, I highly recommend installing a booster pump. It will maintain a high flow rate and reduce the amount of water wasted.


As with most RO systems, maintenance mostly involves replacing the filters after the recommended period.

For the Express Water RO5DX, that’s six months for the pre-filters.

As for the RO membrane, you need to replace it annually. That’s twice as often as other RO membranes that last 2-3 years. The post-carbon filter also needs to be replaced annually.

Because of the short lifespan of the last two filters, the Express Water RO5DX is slightly more expensive to maintain.

At least, the manufacturer includes four free replacement filters with the RO system.

In addition to filter replacements, the manual recommends sanitizing the system once a year using household bleach.

It takes around half an hour, and you’ll need to replace all the filters afterward. This keeps the system hygienic and free of mold and bacteria.

What do we like the Most About the Express Water RO5DX RO System?

express water

Affordable: Reverse osmosis filters are no longer the expensive appliances that they were a few years ago. The Express Water RO5DX is a great example of how they’ve gotten cheaper. It costs less than most RO systems but delivers excellent filtration performance.

Easy installation: Just about anyone can install the Express Water RO5DX. They’ve made everything easy for you, even pre-assembling the system to ensure you spend less time tinkering under the sink.

Good flow rate: You don’t have to wait forever to fill up a water bottle or water jug.

What We Don’t Like About It 

reverse osmosis system reviews

1. Short Filter Life

The 6-month lifespan of the pre-filters is expected considering the price tag. Most RO systems in the same price range also use 6-month filters.

What’s a bit disappointing is the short lifespan of the RO membrane and post filter.

Most RO membranes and post filters easily last 2-3 years, and others can last as long as 3-5 years. For the Express Water RO5DX, the membrane and post filter lasts only one year.

As I mentioned, expect maintenance to be slightly more expensive compared to other RO systems. 

2. Relatively Low Production Capacity

For large families that drink a lot of water throughout the day, this may not be the best choice. It’s also not ideal for families that use pure water for other activities in addition to drinking.

The Express Water RO5DX can only produce up to 50 gallons per day, sometimes less depending on water pressure and temperature.

The Express Water RO5DX is Perfect for You If…

express water
  • You are looking for an affordable under-sink reverse osmosis system.
  • You want an RO system that is easy to install and has a good flow rate.

Avoid Buying This One If…

express water
  • You are a large family, or you use more than 50 gallons of purified water every day. Look for an RO system with a higher production capacity.

Our Bottom Line 

5 stage reverse osmosis system

The Express Water RO5DX delivers better performance than you’d expect from an RO system of its price.

Sure, it doesn’t have a remineralization stage, and the daily production capacity is a bit low. But when it comes to what matters most, producing clean and safe drinking water, it’s just as good as pricier RO systems.

If you are looking for a basic RO system that is easy to install and works reliably, we highly recommend the Express Water RO5DX 5-stage reverse osmosis filtration system.

Ed Carmichael

About the Author Ed Carmichael

Ed is a water specialist in Tampa, FL. He built to help his friends and family learn about DIY solutions to common water quality issues in the home.

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