NOTE: As an Amazon Associate, I earn from qualifying purchases.  Learn More.

express water

Express Water ROALK10DCG 10-Stage Reverse Osmosis System Review

If you love the fresh and natural spring-like taste of mineral water, the Express Water ROALK10DCG 10-stage reverse osmosis system is a great choice.

Of the ten stages in the system, five are dedicated to improving the taste of the water. They add minerals to the water, producing alkaline water full of healthy minerals and antioxidants.

The other five stages filter out over 108 contaminants, including lead, arsenic, chlorine, chemicals and waterborne microbes.

Unlike most RO systems, the Express Water ROALK10DCG produces purified water at a reasonably fat flow rate of 0.8 GPM.

That combined with a high daily capacity of 100 GPD makes it ideal for most families, including large families.

Considering its capability and features, the Express Water RO system is surprisingly affordable. It delivers more value for your money compared to other home RO systems.

Read on or our full review of the Express Water ROALK10DCG alkaline RO system.

To compare it to other popular RO systems, read our recently updated best reverse osmosis water filters buying guide.


  • Excellent filtration performance
  • Produces healthy and excellent tasting alkaline mineral water
  • Surprisingly affordable
  • Easy to install and maintain
  • Fast flow rate and high daily capacity


  • The remineralization filter doesn’t always work as advertised
  • Short filter life

Product Specifications 


  • Number of stages: 5 filtration stages plus remineralization
  • Production Capacity: 100 gallons per day (GPD)
  • Wastewater to pure water ratio: 3:1
  • Reserve tank capacity: 3.2 gallons
  • Booster pump: no
  • Remineralization stage: yes
  • Filter lifespan: 6 months
  • Membrane lifespan: 1 year
  • Installation kit: yes

Best Features 

reverse osmosis system reviews

1. 5-Stage Filtration 

Don’t let the ’10 stage’ marketing speak confuse you. When it comes to the actual filtration, the Express Water ROALK10DCG is on par with most other RO systems in its price range.

That doesn’t mean it’s bad. The complete opposite.

It removes 99% of dozens of contaminants in your water, including heavy metals, chemicals, dissolved salts, sediment, and chlorine.

If you want to see just how effective the system is, take a TDS reading only of your normal tap water and the purified water.

Some users have seen their water come down from a TDS of over 500 to under 20.

Note: The TDS reading may be slightly higher than in other RO systems because of the remineralization stage.

Here are the five filtration stages water goes through.

Sediment filter: Removes large suspended particles in water, including rust, sand, dust, and sediment. This reduces water turbidity and extends the lifespan of the other filters.

Carbon block and granular carbon filters: These two carbon filters remove unpleasant tastes and smell from the water. They filter out chlorine, chloramine, VOCs, pesticides and other chemicals. This makes your water safer, improves its taste and smell and protects the RO membrane from damage.

RO membrane: Filters out the tough contaminants including lead, arsenic, fluoride, dissolved salts, and harmful bacteria, viruses, and cysts.

Activated post carbon filter: This filter comes after the remineralization stage. It provides a final polish just before the water comes out of the faucet.

2. 5-Stage Remineralization

After going through the RO membrane, water passes through a 5-stage remineralization filter. At each stage, a mineral is added to the water.

This replaces the minerals that were stripped out by the RO membrane.

Adding minerals to the water has two major benefits.

  •  It improves the taste of water. The water tastes like premium bottled water thanks to the added minerals.
  • The added minerals make the water slightly healthier than usual purified water. The water is also slightly alkaline than normal RO water. It has a higher level of antioxidants, which have many health benefits.

3. High Flow Rate and Daily Capacity

Despite the lack of a booster or permeate pump, the Express Water ROALK10DCG has a decent flow rate of around 0.8 gallons a minute.

This is much better than most RO systems, which produce water in a slow trickle.

Filling up a water glass or a large water bottle takes very little time.

Something else we love about the Express Water ROALK10DCG is the high daily capacity. It can produce up to 100 gallons a day of purified water, making it perfect for large families.

Note: The stated figures for flow rate and daily capacity depend on your water pressure and temperature. The system performs best with water pressure above 60 psi and water at room temperature (never run hot water through an RO system).

4. Flooding Protection

Even a high-quality filtration system is prone to leaks. It is the nature of the plumbing.

It can be especially bad if the leaking happens out of sight and you only notice it when it is too late.

The Express Water ROALK10DCG has a flood protection mechanism that ensures small leaks under your sink don’t result in a messy flood.

The system comes with a Leak Stop Valve.

It’s a small fabric disk you place on the floor next to the RO system. If there is a leak, the disk will absorb water and automatically shut off the water supply.

Installation and Maintenance 

Express Water ROALK10DCG

The Express Water ROALK10DCG is relatively easy to install. It just takes time – around 1-2 hours depending on how handy you are around plumbing projects.

The manufacturer makes DIY installation easy and straightforward by including color-coded tubes and quick connect fittings. You can tell where every part goes just at a glance.

Some of the parts are also pre-assembled, making your work easier.

The system is designed to go under your sink where you can mount it on the wall or leave it to stand on the floor.

If you have no space under your sink, you can install it anywhere there is a cold water line and a drain line.

Just make sure your water has enough pressure to reach the RO faucet. You may need to get a booster pump to maintain proper water flow out of the faucet.


Which Filters in the Express Water ROALK10DCG do I need to replace?

  • Sediment filter (6 months)
  • Carbon block filter (6 months)
  • GAC carbon filter (6 months)
  • RO membrane (annually)
  • Post carbon filter (annually)
  • Alkaline filter (6 months)

The filters have a relatively short lifespan. You have to replace the pre-filters every 6 months and the membrane and post-filter annually.

Thankfully, filter replacement is easy, and additional filters don’t cost a lot of money.

A filter housing wrench is included with the system. Use it to open the filter housings and remove the old cartridges.

Wash the housings with mild soap and rinse before putting in new filters.

You’ll also have to change the alkaline filter every six months.

What we Like the Most About the Express Water ROALK10DCG RO System

Express Water ROALK10DCG RO System

Great value: The Express Water ROALK10DCG provides excellent performance and more features than other RO systems that cost just about the same.

Produces great tasting water: If you can’t do without your favorite bottled water, you’ll love the taste of the water produced by the Express Water ROALK10DCG. You’ll save money on bottled water, and save the environment while you are at it.

Easy DIY installation and maintenance: The instructions are clear, and the color-coded tubes make installation much more manageable. Replacing the filters is also easy.

What We Don’t Like About it

express water

1. Short Filter Life

You have to change the pre-filters and the alkaline filter every 6 months, which is twice as often as some other RO systems that have 12-month filters.

But a 6-month lifespan is roughly the same as most other filters in this price range.

But when it comes to the RO membrane, the Express Water ROALK10DCG is way below average.

Even the cheapest RO systems have 2-3 year membranes. With the Express Water ROALK10DCG, you have to change it annually together with the post filter (which also lasts 2-3 years in most RO systems).

Expect maintenance to be slightly more expensive compared to other reverse osmosis systems.

2. Water is not as Alkaline as Promised

Hearing the manufacturer tell it, you would think the Express Water ROALK10DCG can replace a proper water ionizer.

The company constantly touts the alkaline water their system produces.

But as several customers have noted, the water is not very alkaline. Some even got a neutral pH reading.

The mineral water tastes great and has many more health benefits than normal RO water, but it doesn’t come close to what you can get from an alkaline water machine (also called a water ionizer).

The Express Water ROALK10DCG Is Perfect for You If…

Express water
  • You are looking for an affordable but high-performance under-sink RO system.
  • You want a reverse osmosis system that produces mineral water.
  • You are looking for an RO system with a decent flow rate and which produces enough water per day for a large family.

Avoid Buying This One If…

reverse osmosis system reviews
  • You don’t care much for mineral water. A basic 5-stage RO system will do for you.

Our Bottom Line 

ro filter system

If you want to replace your bottled water purchases, the Express Water ROALK10DCG is the best reverse osmosis system to get.

Not only does it produce water that tastes just as good as premium mineral water, but it also produces drinking water at a fast flow rate, making it easy to stay hydrated.

The high daily production capacity more than meets the drinking water needs of large families.

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.

follow me on:

Leave a Comment: