It can be frustrating finding the perfect water filtration system. Chances are that if you are reading this review, we can hedge our bets that this is not the first place you have looked, and we feel your pain.

We have done plenty of research into water softeners and filtration systems on the market. This is why we have decided to put together this in-depth review of the Waterdrop WD-D6-B RO Reverse Osmosis Water Filtration.
For starters, this product is from a Water Quality Association (WQA) certified company. This means that Waterdrop has demonstrated that it is capable of providing its customers with exceptionally safe, high quality, and durable products for cleaning your indoor water.
You need to ensure that you have at least 35 psi of water pressure for this water filter system to work efficiently. If you live in a low water pressure area, you may have to buy a booster pump; besides, you might need to replace the filters quite frequently.
To find out more about this system, look at the features below.
FIST integral composite filter with 5 filtration stages
Waterdrop WD-D6-B Introduction Video
Performance
This Waterdrop model is advertised to offer you 0.42 gallons per minute. However, the actual figure might be a bit lower. The production rate on the unit depends on the pressure of your incoming water, temperature, and water quality. In an ideal world, the water production can easily exceed 0.42 gallons per minute, but this would be rare.

A 5-Stage Water Filtration System
This Waterdrop water filter system features a 5-stage reverse osmosis water filtration system. Next, we give a brief description of the role of each stage in the process.
Stage one contains a sediment filter for removing rust, dirt and other particles found in your municipal water. Stage two and three carbon filters help in getting rid of any odors and weird taste in your water, as well as chemicals like chlorine. Stage four filter is the reverse osmosis membrane. Reverse osmosis is the process of separating fresh, clean water from additives that make your water have a cloudy appearance.
The membrane in the fourth stage removes the nasty tasting and smelly elements in water. This membrane helps get rid of impurities such as cadmium, sulfates, magnesium, calcium, sodium, asbestos, industrial waste, chlorine, radioactive contaminants, pesticides, bacteria, and viruses among others.
The stage five post-carbon filter ensures that your water tastes great. This extra carbon filter provides you with the best water for your cooking and drinking purposes.
You need to replace the filters in stages 1, 2, and 3 between 6 and 12 months of use depending on the condition of your inflowing water. The reverse osmosis membrane in stage 4 and filter in stage 5 require replacement at 2 to 3-year intervals, again depending on your inflowing water quality.

Removes 99.99% harmful contaminants, such as salt, atrazine, nitrates, PFAS, lead, fluoride, sodium, chromium, TDS, etc.
Easy Installation
The Waterdrop measures 18 inches by 5.5 inches by 17.5 inches for the reverse osmosis unit. The unit weighs about 22 pounds, which is lighter than most RO units on the market are.
This is a compact system that you can install even in a small under counter space, but you can also fix it anywhere you can get a water feed line. With minimal skills, you will be able to install the unit yourself without bringing in professional help.
Waterdrop Under Sink D6 Reverse Osmosis Filtration System Installation Instructions
Product Overview
Parts List
If there is no hole in your kitchen sink or countertop, you have to drill one (1 3/8″) or use the hole in the soap dispenser.
Continue Reading
1. Install the Feed Water
Shut off the water supply.
Turn on the faucet to release the water pressure.
Make sure the water has stopped before proceeding to the next step. Use a towel or bucket to catch any excess water.
Disconnect the cold water pipe from the cold water supply valve.
Connect the white 1/4” inlet water tubing to the feed adapter and pop the lock clip on the fitting.
NOTE: Make sure it is fully inserted until you reach the mark on the tubing.
Twist the feed water adapter onto the cold water supply valve (with its washer).
And tighten it using an adjustable wrench.
If the cold water pipe is 1/2″, unscrew the converter from the A end of the fee adapter, and then screw it on the B end of the feed water adapter.
2: Install the Faucet
Insert the faucet stem and power cord into mounting washer 1.
Insert the faucet stem and power cord into the hole on the countertop. Fix mounting washer 1 on the countertop.
Under the sink, put mounting washer 2 and 3 on the faucet stem. Slip on the nut and tighten it
Insert one end of the blue 1/4” PE tubing into the quick-connect fitting on the faucet and pop in the lock clip on the fitting.
3. Install the Drain Saddle
Stick the foam seal on the front plate of the drain saddle. Ensure that the hole of the foam seal is aligned with the hole of the front plate. Choose a spot on the drainpipe that is convenient for installing the drain saddle.
Drill a 1/4″ hole in the drainpipe. Be sure not to penetrate the opposite side of the pipe.
Slip the front plate on one end of the tubing (without a mark) and insert the tubing into the drilled hole for a 0.6″.
Position the back plate on the drainpipe by tightening the screws and nuts evenly while leaving the tubing in the hole.
Pop the lock clip onto the fitting to secure the connection.
4. Position the RO System Housing
Ensure that there is sufficient space under the countertop to install the system (15.98″ x 5.98″ x 11.97″). Set aside 2 inches of space around the system to avoid placing the system against the cabinet.
1. Install the Inlet Water Tubing
Identify the white 1/4″ PE tubing that has been connected to the feed water adapter.
Insert the other end of the tubing into the inlet water port and pop the lock clip on the fitting.
NOTE: Make sure it is fully inserted until you reach the mark on the tubing.
2. Install the Outlet Water Tubing
Identify the blue 1/4 ” PE tubing
Insert the other end of the tubing into the outlet water port and pop the lock clip on the fitting.
NOTE: Make sure it is fully inserted until you reach the mark on the tubing.
3. Install the Drain Tubing
Connect the red 1/4″ PE tubing to the drain saddle.!
Insert the other end of the tubing into the drain port and pop the lock clip on the fitting.
NOTE: Make sure it is fully inserted until you reach the mark on the tubing.
6: Connect the Faucet Power Cord
Connect the faucet to the system: Insert the power cord which is attached to the RO faucet into the connector at the back of the housing.
7: Start up the System
Turn on the cold water supply valve. Check for leaks.
Insert the power plug into the socket. Refer to the user manual for detailed notes.
Turn on the faucet, and allow it to run for 20 minutes.
After flushing, the system is ready for use.
The system will drain residual water after every use to ensure the system’s service life and filtered water quality.
Every time you turn on the faucet, the system will need some time to dispense water. There may be a 3-second delay before water dispenses, which is normal.
Before turning off the faucet, make sure the flushing is complete and that there are no leaks in any of the parts.
Congratulations! You have successfully installed the RO system. Enjoy pure and crisp water with Waterdrop now.
Installation Video
Water Efficiency
Like all other reverse osmosis units, some of your incoming water may be used for flushing the RO membrane. While most of the flushing water is wasted, it is recommended that you use the wastewater from the unit for filling ponds or watering your garden.
However, if there is fish in the pond, you might have to check the water’s quality using an external water-testing meter. This is because your wastewater may have a substantially significant amount of contaminants compared to what typically comes to your faucet.

600 GPD fast water flow
• Fills a cup with water in 8 seconds
• No waiting for clean water
Who can use This Unit?
Anyone in need of a good reverse osmosis water system to remove organic chemicals, nitrates, copper, and lead, as well as municipal additive fluoride in water would greatly benefit from this Waterdrop model.
Related Under Sink Water Filter Articles
Best Under Sink Water Filters
Video Review by I Teched Up
Waterdrop Comparison Chart
Waterdrop WD-D6-B: Conclusion
Thanks to NSF certificates and a WQA Gold Seal award, you can be sure that the Waterdrop Reverse Osmosis Water Filtration System is a superior U.S-built product.

The unit is virtually noiseless when in operation. The filtration process of this unit helps get rid of 99 percent of contaminants including microorganisms and pharmaceuticals.
The unit is capable of providing you with water for large households. One of the best things we love about this unit is that virtually anyone can install it.
- 𝟔𝟎𝟎 𝐆𝐏𝐃 & 𝟐:𝟏 𝐥𝐨𝐰 𝐝𝐫𝐚𝐢𝐧...
- 𝟔-𝐬𝐭𝐚𝐠𝐞 𝐜𝐨𝐦𝐩𝐨𝐬𝐢𝐭𝐞 𝐟𝐢𝐥𝐭𝐞𝐫 &...
If you have any questions or comments, please add them below in the comment section. Similarly, please let us know if you spot any mistakes or omissions. Thanks!
Last Update: 2023-12-04 | Affiliate links/Images from Amazon Product Advertising API