Waterdrop G3 VS D6 Tankless Reverse Osmosis System

Every household requires clean water, both for drinking and cooking. And while tap water might appear clean to your eyes, it just isn’t.

That is why you need to invest in a water filtration system. Talking of water filters, WaterdropFilter systems are units you can’t ignore.

The brand has award-winning filter systems that will make your tap water safe for drinking and cooking. The units also have a fast water flow rate and a low drain ratio.

You’ll never come across a Waterdrop reverse osmosis system with a drain ratio of 4:1 or 5:1.

And since we believe that you are looking for a highly-efficient water filtration system, we’ve prepared this review article.

In this post, we compare two of their best water filtration systems, the Waterdrop WD-G3-CR and WD-D6-B.

Both systems are highly effective against water contaminants and will give great-tasting water. They also share a significant number of similarities. Do they have differences? You’ll know that in a few; keep reading.

Quick Comparison Chart

FeatureWaterdrop WD-G3-CRWaterdrop WD-D6-B
Dimensions18.12 x 5.67 x 17.72 inches15.99 x 6.10 x 11.97 inches
Weight37.1 pounds22.6 pounds
Water filtration stages7 water filtration stages6 water filtration stages
Type of faucetBright chrome faucetSmart designer faucet
Water flow rate400 gallons per day600 gallons per day
Drain ratio1:12:1
Wattage72 watts85 watts
Filter life indicatorNot mentionedAvailable
TDS level displayNot mentionedAvailable
Price Directly on WaterdropPrice Directly on Waterdrop
Price on AmazonPrice on Amazon

1. Waterdrop WD-G3-CR RO 400 GPD Tankless Reverse Osmosis Fast Flow Water Filtration System Review

Waterdrop WD-G3-CR RO 400 GPD Tankless Reverse Osmosis

The Waterdrop G3 is a tankless RO system that filters water in 7 stages. With a drain ratio of 1:1, this unit is highly efficient and reliable.

The unit is a bit bulky now that it measures 18.12 x 5.67 x 17.72 inches and is a little heavy at 37.1 pounds.

It has a fast flow rate of 400 gallons per day, comes with innovative composite filters, and can intercept impurities larger than 0.0001 microns like chlorine and heavy metal.

Thanks to an internal pump that enables the water to flow faster, you don’t have to wait for clean water with this system. It can fill a glass of water in 12 seconds.

Waterdrop G3 Tankless RO
  • Design

The Waterdrop G3 comes in white and boasts a smart tankless compact design that enables you to always have fresh water. Remember, tanks can be a source of secondary contamination as they provide a breeding ground for pollutants.

The tankless nature of the system helps save at least 75% of your under-sink space. This filter system will suit you best if you have a medium-sized kitchen.

  • Bright Chrome Faucet

Included in the package of this filter is a nice faucet for installation in the kitchen area. The faucet is made of chrome material and a stainless spout that gives it a bright shine.

  • Innovative composite filter
excellent 7 stages filtration

The G3 is intelligent with innovative composite filters that filter the water, giving you excellent results. 3 filters are enough to filter your water in the 7 stages.

The composite filter can remove all impurities larger than 0.0001 microns like chlorine, TDS, heavy metal and improve the taste of the water.

  • Water Flow Rate

This unit has a fast water flow, produces up to 400 gallons of pure water per day, and saves 3 times more waste water than traditional RO systems.

No wonder it’s tankless. At this rate, your glass of water fills up pretty fast (in 12 seconds). At this speed, you don’t need a tank to hold the water.

It has a drain ratio of 1:1, meaning that for every gallon of water produced, only one gallon goes to waste. The unit triples water utilization while cutting down on your monthly water bills.

  • Internal pump

All Waterdrop RO systems come with an innovative internal pump that adjusts according to the feed water pressure. This makes the system more efficient in producing RO water.

This pressure pump makes the production of 400 gallons of water per day and the 1:1 drain ratio possible.

  • Smart Leakage Protector

The system has a built-in leakage protector that monitors water and switches off automatically if a leak is detected.

  • Installation and maintenance

The Waterdrop WD-G3-CR is designed for DIY installation in up to minutes. Connect the system to the faucet and electricity for it to work.

After getting the required tubing, you can also connect the unit to a refrigerator or icemaker.

The units’ filters are also easy to replace with a single turn.

  • Certifications

The RO filter system does not contain more than 400 chemicals, including benzene, bisphenol, formaldehyde, lead, cadmium, among others.

It has a TDS reduction rate of up to 90% and is NSF/ANSI 58&372 certified.

Pros and Cons of G3


  • Tankless thus space-saving
  • Convenient installation
  • Built-in pressure pump speed up water flow
  • Removes over 99% of water contaminants
  • High water efficiency
  • Quick filter replacement
  • Compatible with refrigerator and icemaker
  • Backed by a 1-year manufacturer and seller combination warranty


  • No remineralization
  • Expensive

2. Waterdrop WD-D6-B 600 GPD No Tank High Flow Reverse Osmosis System.

Waterdrop WD-D6-B 600 GPD NoTank RO

The Waterdrop WD-D6-B is a tankless under-sink RO system with a faster flow rate of 600 GPD. The unit measures 15.99 x 6.1 x 117.97 inches and weighs 22.6 pounds.

It has a drain ratio of 2:1 and filters water in 6 stages.

The D6 comes with a smart designer faucet with built-in LED, operates noise-free, and you’ll rarely come across leaks when using it.

  • Design

The D6 is a black RO system that comes in an innovative tankless design. It is compact enough to fit in your tiny under-sink space.

The unit’s small footprint makes the kitchen more usable, enabling you to use the space better. It also features a sleek, smart designer faucet with a screen that shows real-time TDS level and the remaining filter life.

  • Smart designer faucet

It has a smart designer faucet for installation in your kitchen sink area. The faucet features a clear display that shows real-time TDS levels and the remaining filter life.

The display (screen) is waterproof, so you do not have to worry about electrical leakage when using the unit.

  • Filtration Process

The D6 filters water in 6 stages and eliminates pollutants from the water, including chlorine, nitrates, benzene, lead, chromium, sodium, PFAS, among others.

In the 1st stage, a sediment filter eliminates dust, sand, silt, rust, and other large particles from the water. Carbon filters remove chemicals, odors, and tastes from the water in stages 2 and 3.

The RO membrane helps eliminate impurities like calcium, magnesium, asbestos, sulfates, cadmium, pesticides, herbicides, industrial wastes, and viruses in stage 4.

In the 5th and 6th stages, a post-carbon filter helps eliminate any lingering taste and odor in the RO water. At this point, your water is clean, healthy, and ready to use for drinking and cooking purposes.

  • Water Flow Rate

The D6 has a water flow rate of 600 GPD. It filters water fast, enabling you to fill a glass in 8 seconds. All this is made possible by the large filter surface and the innovative internal pump.

The unit also boasts a low drain ratio of 2:1. For every gallon of pure water produced, the system wastes 2 gallons. It can therefore be considered a relatively efficient unit.

Plus, you can use the waste water to water your flowers, mop the floor or wash your car.

  • No noise and no leaks

This unit has passed thousands of tests indicating that it avoids water leakage and reduces noise when in operation.

In fact, you can’t hear anything after closing the cabinet.

Compared to ordinary reverse osmosis systems, the D6 has a better sealing effect and fewer connectors in the water circuit. It is therefore very safe to use.

  • Installation and Maintenance

The D6 is relatively easy to install, and just like the WD-G3-CR, it should not take you more than 30 minutes to complete the process. You just need to drill 2 holes, one for the faucet and the other for the drain pipe.

To operate the unit, you need an electrical outlet. You can also connect it to a refrigerator or icemaker.

It is also easy to clean since it’s tankless. Filter replacement is also an easy process that takes seconds to complete.

Pros and Cons of D6


  • Produces 600 gallons of water per day
  • Relatively quiet and leak-free
  • Easy to install and maintain
  • Compact and space-saving
  • Provides great-tasting water
  • Tankless thus prevents secondary contamination
  • Removes most contaminants from the water
  • It is backed by a 1-year manufacturer and seller combination warranty


  • Expensive
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