Waterdrop WD-D6-B 600 GPD RO Water Filtration System Review

Waterdrop is a WQA (Water Quality Association) certified company for providing its customers with high-quality, durable, and safe products for cleaning your drinking water.

The company has, with time, become the undisputed leader in the tankless RO space for making highly reliable RO systems.

And the Waterdrop WD-D6-B, which is one of their latest additions, is no exception. It filters water in 6 stages and effectively reduces pollutants like TDS, lead, sodium, chlorine, chromium, benzene, PFAS, etc.

With filtered water to waste ratio of 1:2, the system works more effectively than most RO systems, which usually operate at a ratio of 1:3 and 1:4.

In this post, we dig deeper into the features of the Waterdrop WD-D6-B to help you make an informed buying decision.

In a hurry? The key features listed below should give you an overview of what to expect from this unit.

Key Features at a glance

Waterdrop WD-D6-B 600 GPD RO
  • Measures 15.99 x 6.1 x 11.97 inches
  • Weighs 22.6 pounds
  • Innovative tankless design
  • Fast flow rate of 600 GPD
  • 1:2 filtered water to waste water ratio
  • Filters water in 6 stages
  • Convenient installation
  • Smart designer faucet
  • No noise and no leaks

Waterdrop WD-D6-B 600 GPD 6 Stage Reverse Osmosis Water Filter System Detailed Review


The D6 reverse osmosis filter comes in a compact and slim design to fit even the tiny spaces. Interested an RO system for RV? The D6 might be all you need.

The system is extra tiny with a small footprint and will thus save your under-sink space. It’ll make your tiny kitchen more usable and help you utilize the space even better.

You’ll also fall in love with its sleek, smart faucet with a high-end screen that shows the filter’s remaining life and the real-time TDS level.

Innovative Internal Pump

The system comes with a smart internal pump that detects the pressure of the incoming water and adjusts it appropriately for the fastest RO process. This helps speed up pure water production and minimize waste.

Smart Designer Faucet

The unit features a smart designer faucet for installation in the kitchen sink area. The faucet has a high-end (screen) display that shows the real-time TDS level and the remaining filter life.

The screen is waterproof, so you won’t have to worry about electrical leakage when dispensing water.

Effective 6-Stage Filtration Process

Waterdrop D6 adopts a 6-stage filtration. The RO membrane has a filtration accuracy of 0.0001 microns.

The 6-stage filter eliminates pollutants from the water, including lead, chlorine, salt, nitrates, sodium, benzene, chromium, PFAS, among others.

The first stage contains a sediment filter that removes dirt, rust, and other particles in your tap water.

In stages 2 and 3, carbon filters help in eliminating odors and odd tastes in your water. Chemicals like chlorine are also removed in this stage.

In the 4th stage, the reverse osmosis membrane helps eliminate impurities like magnesium, calcium, asbestos, cadmium, sulfates, pesticides, bacteria, industrial waste, and viruses.

And since there might be some lingering taste or odor in your water, a post-carbon filter in the 5th and 6th stages helps eliminate them and provide you with clean and healthy water for cooking and drinking purposes.

Water Flow Rate

The system is upgraded to have a water flow rate of 600 gallons per day. This is made possible through the joint efforts of the highly efficient filters and the innovative internal pump.

It filters water fast, and in a few seconds, you’ll get a glass of clean and pure drinking water. This system will satisfy your hydration needs while saving time.

No Noise and No Leaks

No one enjoys having a noisy water purification system in their home. With the WD-D6-B, you won’t be disappointed.

The system has passed thousands of tests that indicate that it reduces noise and avoids water leakage. After closing the cabinet, you can barely hear anything.

Also, compared to ordinary reverse osmosis systems, the D6 has fewer connectors and a better sealing effect. It ensures a safe user experience.


The Waterdrop WD-D6-B doesn’t have a water storage tank. Therefore, water is produced and sent directly to the faucet when it is turned on.

It has a built-in tank that provides optimum pressure for speeding up the RO process. For this reason, you get to fill a glass of pure water in seconds.

Working with a 1:2 pure water to waste water ratio, this system is far more efficient than most basic RO systems without a built-in booster pump.

While most systems feature a 1:4 water ratio, wasting 4 water gallons for every gallon produced, this system loses only 2 gallons for every gallon of water produced.

In general, this system is more efficient and environmentally friendly when it comes to the water production. After installation, you need to flush it with water for 30 minutes.

The flushed water isn’t suitable for drinking, and the manufacturer recommends that you use it for other purposes like watering flowers.

Installation and Maintenance

The D6 is one of the easiest RO systems to install. In fact, you can complete the installation process within 30 minutes.

You’ll have to connect the system to the faucet and electricity according to the instructions in the included manual.

The system is also easy to maintain now that it’s tankless. You won’t have to clean it from time to time. Actually, all that’s required of you is to wipe down the faucet.

Filters are easy to replace and need changing every 12 months. The unit contains no secondary pollution now that it doesn’t come with a storage tank.

Additional cleaning and sanitization of the system beyond changing the filters is really not necessary.

Product Summary

The Waterdrop WD-D6-B is a tankless under sink RO system that is powerful, space-saving, highly efficient, and reliable.

It comes in a sleek modern design, has a fast water flow rate of 600 gallons per day, comes with a smart designer faucet, and removes most contaminants from the water.

The system is easy to install and maintain and requires filter replacement every 12 months.

Pros and Cons of Waterdrop WD-D6-B 600 GPD 6-Stage Reverse Osmosis


  • Sleek and sophisticated appearance that complements any modern setting
  • Provides 600 gallons of drinking water every day
  • Has a smart designer faucet with a built-in LED
  • Easy to install and maintain
  • Works quietly and without leaks
  • Provides great-tasting water
  • The tankless design saves more under sink space


  • No remineralization filter
  • Expensive filter
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