Waterdrop T4-A Alkaline Mineral Tankless Reverse Osmosis System, Dual Flow | NSF/ANSI 372 Certified, 10-Stage, 450 GPD Under-Sink RO Filtration System, 2:1 Pure to Drain, BPA Free, Plug-in required

Very easy to install, no leaks, and worked well for my sink. I love the very simple plug and play design, it seems very well thought out. Just make sure that when you drink from the water, you let some of the water drain out first as it has been sitting in the plastic hoses. Other than that, seems like a very high quality machine with reasonable filter prices. The water is very pure and tastes wonderful.

This home reverse osmosis water filtration system has been a great purchase so far. The water tastes exceptionally clean and fresh, and I appreciate having both purified and alkaline water available. Installation was straightforward and relatively simple to complete. The system does make a slight noise while the storage tank is filling, but it's minor and not disruptive. Overall, I am very pleased with the product's performance and water quality. The real test will be how well it continues to perform over time, but based on my experience so far, I would definitely recommend it.

Really love this water filter (WD-T3-M). Most reviews here are from an older model the G3, not what is being actually sold in this listing. Love that they have version that is remineralized without being Alkaline, in addition to an Alkaline version. The unit is easy to install and maintain the filters and is a great balance between available features and price. I knew I wanted a WaterDrop filter but many of the more expensive versions came with features I just didn't want or need and a price tag to match. Getting the features I care about for a great price. Win win. This model series isn’t even available on Waterdrop's own website yet which made me skeptical at first. I called waterdrop and they said it was new and not official released. Not sure why Amazon had it first but took a chance. Install was a bit complicated but just because we have an older home and needed to have an outlet added. If you already have an under sink outlets it should be no problem. I was happy to hire a handyman for my install however. We also got the small pressure tank to run the filtered water to our fridge for cold water and ice. Highly recommend. My husband says it’s the best water he’s ever tasted. I love the taste of our ice now. We are drinking so much more water. Because it is remineralized too I can use this directly in my fancy espresso machine without adding minerals back in. I find the dispense speed to be just fine for our needs. Varies a bit and not super fast but about as fast as it was coming from our fridge dispenser. The video shows how quickly it fills a 16oz glass and the volume (quiet) of the filter system when actively running.

In a marketplace saturated with convenience, bottled water has long sold an illusion: purity wrapped in plastic, convenience priced at a premium. This tankless reverse osmosis, alkaline mineralized filtration system quietly dismantles that illusion — and replaces it with something far more rational. At its core, this system is about control. It brings water purification out of the supply chain and into the home, where it belongs. No hauling cases up stairs. No storage clutter. No recurring expense disguised as habit. Just a steady, immediate supply of clean, well-balanced drinking water. The performance is where it earns its credibility. Reverse osmosis does the heavy lifting — stripping away contaminants, dissolved solids, and impurities with precision. What remains is then rebalanced through mineralization, restoring a clean, neutral taste and a stable pH that feels natural rather than sterile. The result is water that is not only safe, but genuinely enjoyable to drink. The tankless design is more than a technical upgrade; it is a practical one. By eliminating the storage tank, the system reduces the risk of stagnation and improves efficiency. Water flows fresh, on demand, without the footprint or maintenance concerns of older designs. It is a modern solution to an old problem. Installation, often a barrier for home systems, proves refreshingly straightforward. The process requires access to a power source beneath the sink and the willingness to drill a clean, precise hole in the countertop for the dedicated faucet. With a hole saw drill bit, a screwdriver, and a utility knife to trim hoses to size, the setup is manageable for anyone with basic DIY confidence. The steps are logical, the fittings intuitive, and the result feels earned rather than engineered by frustration. Then there is the environmental reality. Bottled water is, in blunt terms, an exercise in unnecessary waste — a cycle of extraction, packaging, transport, and disposal that leaves behind a trail of plastic with a lifespan far longer than its usefulness. This system interrupts that cycle at the source. Each glass poured at home is one less bottle produced, shipped, and discarded. Cost, too, tells a quiet truth. What appears inexpensive at the store compounds quickly over time. A filtration system like this reframes water not as a product to be purchased repeatedly, but as a utility — accessible, consistent, and far more economical in the long run. This is not a luxury appliance. It is a correction. Verdict: For those willing to step out of the bottled-water habit, a tankless reverse osmosis system offers a compelling alternative — cleaner water, lower long-term cost, and a meaningful reduction in plastic waste. In both personal and environmental terms, it is a decision that carries its own kind of clarity.

I could be crazy, but the flow seems lower than I was expecting based on the spec sheet. The re-mineralized water also has a suspicious/slightly off taste. As a result, I just drink from the RO side. Tried running the Alkaline side for a long period of time to flush the filter. Didn't change the taste. Don't think there's anything wrong with it, but it doesn't have that nice "mineral water" flavor. Install was easy enough but requires a bit of patience with all the hoses. Don't rush yourself and use the bathroom ahead of time and you'll be fine. Filter replacement will likely be a snap (we haven't needed to change them yet). Biggest benefit is not having that massive tank under the sink anymore. Going tankless has been a real space saver.

Installed easily though did require a trip to the hardware store for a couple couplings as the threads supplied did not match my plumbing. That was the most difficult part of the installation. The unit mounted on the sidewall under our sink and does not take up much room and allows easy view of the display panel. Now for the more important part of the review. The taste of the water is remarkable. The purified water tastes like water filtered through our ZERO water filter pitcher, (much better than bottled water). The Alkaline pH+ water is remarkable. Reminding me of well water from northern Minnesota; crisp! I learned in speaking with the Waterdrop people that the T4 series is their latest offering, designed to be cost competitive, (it is much lower cost than their earlier systems). The difference being that the more expensive units have a higher volume per day of filtered water. We decided we would never exceed 450 gallons/day so this unit met our needs, and was very reasonably priced. We highly recommend it.

A very effective reverse osmosis system at an affordable price. The T4-A RO system has effectively reduced the number of suspended solids and contaminant on the city water on my house in Northern Illinois even lower than the commercial water refill from our local Walmart. I also took water samples and have it tested to compare the City water vs the water from this T4-A. The system is also very easy to install and took me about 1-hour to install and this includes the 30 minute required for the initial start-up flush. Another benefit I saw is this system have filtered out heavy metals and PFAS (micro plastic) which was found on trace amount on the city water. This system also has the option to give you Mineralized water if so desired. For comparison the T4-A is a tankless system and does not need to do a regeneration cycle compared to RO system with tanks. So far, I have measured the T4-A flowrate at 0.40 gallon per minute. This unit also have a Ultra-violet system but I am not sure how helpful this will be since the dwell time of the water will be short. The only concert I do have on this unit is the availability of the pump or parts if something broke. I do see there are available filters though. To summarize- I highly recommend. Update- I have sent a few questions regarding the Waterdrop T4-A unit and Rosie from customer service has done an excellent job in answering my questions. My RO unit has been working very well saving me a lot of time and money vs buying bottled water.

I'm a huge fan of this RO water system. First thing the simplicity of installation and instructions A++!! So well thought out and the water connection with a1/2 or 3/8 adaptability! I like the taste of the filtered taste without the minerals just slightly better but both tastes great! Still takes two days before the taste will get settled. I'm glad there's minerals to add as an option! Highly recommend!! Update the mineral water taste soooo good once it sett

Would be a 5 star except the pump would occasionally not turn off until I cycled the faucet on and off again.