Some good some bad
"Less water used is positive, the pump delay is annoying, ice make is not working well after the switch. Water tastes good. Not sure if this was a good change or not. Time will tell tell"
Express Water
The high-end Model 6 Tankless RO System from offers a powerful 600 gallons of water per day filtration process complete with remineralization. You can enjoy the convenience of a continuous supply of clean, crisp, and healthy water straight from your tap. The system's remineralization feature helps provide an improved taste and feel, leaving you with water that's pure and refreshing.
Alkaline Water Filter: Express Water's Alkaline Water Filter, featuring Active Mineral Technology, enriches your water by infusing it with essential minerals like Calcium, Magnesium, and more.
Effortless Efficiency: Enjoy a rapid 0.4GPM water flow with our 600GPD RO water filter system, ensuring you have clean, refreshing water on demand, without the wait.
Sustainable Solution: Experience a remarkable 2:1 pure to drain ratio, significantly reducing water wastage compared to a traditional reverse osmosis water filtration system. Save money and the planet simultaneously!
Space-Saving Marvel: Our reverse osmosis system tankless design is the ultimate space-saver, freeing up valuable kitchen space while providing top-tier water purification.
Quick & Hassle-Free Maintenance: Say goodbye to complicated filter changes. With our innovative 2-second quick-twist tankless RO system, filter replacements are a breeze, keeping your water consistently pure.
Stay Informed: Stay on top of your water quality effortlessly with built-in filter life and water quality indicators. Never guess when it's time for a filter change and enjoy peace of mind about your water's purity.
Built-in leak detection safeguards against accidents.
About The System
Introducing the Express Water Tankless Reverse Osmosis System, a top-tier water purification solution. Crafted with premium materials, this system ensures the purest, best-tasting water flows into your home with its innovative 6-stage filtration.
Our under-sink reverse osmosis system boasts a five-layer filtration process for top-notch water quality. First, the Sediment layer captures rust, sand, and other sediments. Next, the Carbon layer eliminates chlorine and odors, improving taste and clarity. In the third stage, the Sediment Polypropylene layer conditions the water by removing silt and other particles. The fourth stage, the RO Membrane layer, removes TDS, heavy metals, and harmful agents, ensuring pristine, contaminant-free water. The fifth stage, alkaline remineralization filter, features Active Mineral Technology, enriches your water by infusing it with essential minerals like Calcium, Magnesium, and more. The Finally, the sixth stage, the Post-Activated-Carbon layer, provides the freshest, best-tasting water just before you drink it. This five-layer system guarantees both safety and freshness in your water.
Our tankless reverse osmosis system is capable of removing over 1,000 impurities such as arsenic, lead, mercury, nitrates, phosphate, chromium, sodium, copper, and more, including harmful agents like chlorine, fluoride, and PFAs. Additionally, it enhances taste and eliminates odors.
Stay informed with the smart filter alert, notifying you when a cartridge change is needed, ensuring your water remains pure. With an impressive pure-to-drain ratio of 2:1, you can savor more pure water while saving both water and money.
Installation is a breeze with the included step-by-step directions for a quick and easy DIY setup. Plus, our USA-based (lifetime) support team is at your service, ensuring you have continuous access to the best water quality.
Specs
Parts
Installation
Overall rating: 3.3225806 / 5 from 31 reviews.
AI Generated Review Summary
The Model 6 Tankless RO System offers a powerful 600 gallons per day filtration process with remineralization, providing clean and refreshing water. Customers appreciate its efficient water flow, space-saving design, and ease of maintenance. The system's performance and installation are highly praised, though some have mixed opinions about the filters.
Summary topics
- System Performance (23%): A significant amount of customers expressed appreciation for the great performance and ease of installation of this system.
- Filter Quality (41%): Customers have mixed opinions about filters, with some praising their quick and clean setup, while others complain about missing replacement filters.
Review topics: ["quality","customer service","water","buy","filters","system","unit","drawback","space","taste"].
Review highlights
- "Pros: Quick and clean setup, instant water and easy filter install." —
- "The YouTube video in the installation tab on the product was so extremely helpful to seamlessly install our system!" —
- "Great system and easy to install" —
Reviews
No stage 1 filters available!!!!
"I've had my Express Water Model 6 RO system #ROT600ALKMBN for a few years now and everytime I need a stage 1 filter they are always out of stock. I havent been able to use the system for a while now as my water started tasting bad which is the reason I purchased this in the first place. Now I'm reading all the complaints from others about the lack of filters and I am very concerned. This company needs to find a solution to keep these filters in stock if they are going to continue to sell new units to unsuspected persons for them to find out they can't get a filter for the unit they just purchased. Especially since the stage 1 filter needs to be replaced every 6 months. Express Water you need to do better for your customers."
Highly recommended
"My neighbor introduced me to express water that they loved it. He convinced me to get it. Let me tell yall about it that his convincing and me going for it was ans is truely worth it. Water taste very good and I regret by not getting it sooner."
Great System . . . Slow on replacement filters
"Been following the reviews (Nov 2025) and setup and alert or replacement filters. Based on the fact the "Notify me via email" button is still active, stock has not replenished. Do not buy the system as you will be stuck with a brick that you wan't use for months or who knows how long. The initial cost of the filtration system was worth the investment as I was spending more than 50/month on buying water and this system paid itself off in 6 months. But here I am a year later and can't place an order for replacement filters."
Disposable (?) One time water filtration system
"I bought this system about 18 months ago and since day one there has been NO replacement for the filters. They are always out of stock. The company will no provide a solution to this problem, not even an alternative to buy on Amazon. My system has now locked itself and will not even work because filters need replacing."
No replacement filters unless I buy a new system
"I've had my system for a year and I guess its my turn to join the "no replacement filter" club. I don't understand how the filters are always out of stock, but if I choose to buy an entire new system, it miraculously comes with the filters???? Why not stop offering the entire system and let the customers who have already given you their money purchase the filters they need?"
Still No Replacement Filters Available!
"From 5 stars to 1 star just like that! I went through a lot of effort to install this system and I was so happy with it! But then I can't get a replacement filter for months with no end in sight. At what point will you offer a complete replacement system? This looks like it have been going on for too long! What is Express going to do to make this right? Does another supplier make a replacement?"
No replacement filters available
"Just plan on your whole filtration system to last you only a year because the replacement filters will not be available to you 12 months later when you need them. I have been in need of a replacement filter for months and they continue to be unavailable. I’m starting to wonder if I wasted several hundred dollars on an entire RO system."
Loud and out of stock filters.
"Pump is already loud. Sediment filters are rarely in stock. Filter beeps loudly with no way to disable it until you replace the filter that you can't get. Mandatory audible feedback is ridiculous. Buy something that lets you choose whether or not you hear it."
Do NOT buy
"Don't buy this product. Replacement filters are unavailable."
Q&A
- How do I clean the system? RO systems with tank can get a bit grimy. Is that avoided with this tankless RO?
- Dear Customer, Thank you for your inquiry. Cleaning a reverse osmosis (RO) system with a tank involves sanitizing the tank, filters, and tubing to avoid grime buildup. However, with a tankless RO system, the risk of grime is significantly reduced as there is no standing water. It’s easier to maintain but still important to flush the filters regularly and ensure there’s no buildup in the system. Please feel free to contact us if you have further questions. Best regards, Express Water Team
- Is there a difference in quality of filtration between the tankless alkaline RO system and RO alkaline system with a tank? How much space in the cabinet box does the tank system take up?
- Yes, there are differences between a tankless alkaline RO system and a traditional RO alkali system: Filtration Efficiency: Tankless RO: Filters water on demand without storing it, reducing the risk of stagnant water. It may have more filtration stages but smaller membranes. RO Alkali with Tank: Stores filtered water, offering consistent availability but may risk contamination if not used often. Flow Rate: Tankless: Typically faster as water is filtered instantly. With Tank: Flow may be slower as it depends on the tank's refill time. Space and Maintenance: Tankless: More compact, no need for tank sanitization. With Tank: Bulkier, requires occasional tank cleaning. Water Waste: Tankless: Generally more efficient with less waste. With Tank: Higher water waste, though some models improve efficiency. Both offer high-quality filtration, but tankless is more compact and efficient, while RO Alkali provides a consistent water supply. Best, Express Water
- Does the remineralization put sodium back in, and if so, how much? My husband is on a low sodium diet.
- Dear Patty, Thank you for your question. To confirm, we do not carry any filters that add sodium back into the water. Regarding the Remineralization, the following minerals are added to the water: calcium, iron, magnesium, potassium, and zinc. If you have any further questions, feel free to contact us via phone or email. Best Regards, Express Water Team Toll Free: (800)992-8876 Mon-Fri: 9am-5pm (PST) support@expresswater.com