Watts Premier RO-Pure 4-Stage Water Filtration System Review

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Watts Premier RO-Pure Reverse Osmosis Filter System

Watts Premier 4-Stage RO System Review

  •    Price: $
  •    Filter Stages: 4
  •    Gallons per Day: 50
  •    NSF Standard: 58
  •    Annual Costs: $$
  •    Warranty: 3 Years

In this review, you will learn all you need to know about Watts Premier’s RO-Pure 4-stage reverse osmosis system. As the name suggests, we are looking at an RO system with 4 different filtration stages that provide clean, clear and great tasting drinking water.

  • Stage 1: A 5-micron sediment pre-filter traps larger particles like dirt and rust to improve the taste, smell and looks of your water.
  • Stage 2: A 5-micron carbon block pre-filter reduces chlorine, chloramines and everything else left that causes unpleasant taste and odors. Both pre-filters also help to protect the delicate RO membrane from clogging, which extends its lifetime and saves you time and money.
  • Stage 3: The semipermeable membrane at the heart of the system removes up to 95% of TDS (Total Dissolved Solids) and almost all harmful contaminants, such as pentavalent arsenic (99.6%), cadmium (98%), fluoride (97%), lead (98.8%) and up to 99.99% of cysts, bacteria, and viruses. According to Watts Premier, the membrane also reduces nitrates and nitrites, however, the company doesn’t provide proof to backup this claim.
  • Stage 4: The carbon post-filter gives your water a finishing touch after it has been stored in the storage tank. This helps to get rid of any residue tastes.

The maximum pressure at which the system can operate is 100 psi, while the required minimum operating pressure is 40 psi. If the pressure in your home’s water system is below 40 psi, an additional booster pump is needed.


Let’s get straight to the point: The RO-Pure 4-stage is best suited for smaller households. Why? It’s very compact and was designed to fit under kitchen sinks that don’t have enough space to accommodate larger filtration units.

What’s more, the system doesn’t provide the high water output that some of us might be used to and yet still, 50 gallons per day should be absolutely sufficient for regular use.

The system was tested against NSF/ANSI Standard 58, which not only guarantees contaminant reduction (see above), but also material safety.

Did we mention that the RO-Pure comes with a 3-year limited warranty?

More Pros

  • No power connection required – As with all standard RO systems, the Watts Premier system does not require a power connection, as it makes use of pressure from the tap. In case of a power blackout in your home, you will still have access to clean drinking water.
  • Water backflow impossible – Check valves between each cartridge prevent water from flowing backwards. This avoids unwanted substances entering the system.
  • 2 output tubes – The unit has two output tubes. The first one delivers purified water straight to the extra RO faucet that gets installed next to your regular kitchen tap. The second tube connects to the sink drain to flush all those nasty contaminants out of the system.

System Installation

Installing the Watts Premier RO-Pure 4-Stage reverse osmosis system is pretty simple and straightforward – remember that you’ll probably need to do some drilling.

All components are an integral part of the unit, which means that less tubing is required and problems are unlikely to occur. Just follow the provided instructions precisely.

The following video provided by Watts Water Technologies outlines each installation step:

Parts List

  • RO module with filter and membrane housings
  • 3x pre-installed filters
  • RO membrane
  • Shut-off valves
  • Feed water valve
  • Fitting adapter
  • Drain saddle
  • Water storage tank (3 gallons, white)
  • Tank stand
  • Tank valve
  • Chrome faucet with electronic filter monitor
  • Color-coded tubing

Filter/Membrane Replacements

Filter and membrane replacements are extremely simple and fast, as they don’t require you to turn off the water supply and wait for the system to depressurize, thanks to the extra valves built into each filter head.

All you have to do is push a button – don’t worry, easily accessible – to release inside pressure, pull out the old filter or membrane and replace it with a new one, which will easily snap in place. No mess due to water spilling everywhere!

By the way, the fact that you dispose of the whole housing when changing filters makes cleaning the system so much easier.

What are the average lifetimes of the filters/membrane?

  • Sediment pre-filter: About every 6 months
  • Carbon pre-filter: About every 6 months
  • RO membrane: Every 2 to 5 years
  • Carbon post-filter: About every 12 months

Of course, how long each component is going last also depends on your water usage and the quality of the feed water. Overly hard water or high amounts of TDS will likely require you to change them more frequently (especially the pre-filters).

Annual replacement costs are within the normal range.

Watts Premier RO-Pure 4-stage


Here is what we don’t like:

  • A handful of customers have complained about the RO faucet leaking due to the built-in air gap.
  • This system doesn’t come with a drain adapter for sinks with a garbage disposal.
  • At times, you’ll have to wait up to 1 hour if you want to talk to Watts Premier’s customer support team.

Our Verdict

To be honest, the RO-Pure 4-stage by Watts Premier is not the absolute best reverse osmosis water filter system out there, but it’s good nonetheless.

It will provide you with safe drinking water free from all or at least the majority of harmful contaminants and eliminates the inconvenience of heavy water bottles. Filter/membrane replacements take 30 seconds max without spills and maintenance costs are reasonable, which will help you to save money in the long run.

Our verdict: 4 out of 5 stars!

Looking for More Product Reviews?

If you are looking for more detailed RO system reviews, you can find our Top 10 list on the BOS homepage!

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And if you have any questions about the Watts Premier reverse osmosis system or any other filter system really, please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald has been with BOS since the very beginning. She is head of content creation and has fully immersed herself into the home water treatment industry only to become an expert herself. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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Leave a Comment:

delores childs says last year

You said the the Watts is not the best RO system.
I am considering changing min. Can you tell me which RO system is the best?
I do not want to have one that need electricity.
Thank you.

    Gene says last year

    I’d recommend you to check out our home page (simply click the logo at the very top to get there). The page features a list of our favorite systems. 9 out of 10 of them do not reqiure electricity.

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