How Does a 5-Stage Reverse Osmosis System Work?
Written by: Alexandra Uta // Last Updated: Aug 29, 2023
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A 5-stage reverse osmosis system sounds great, but how does it actually work?
And do you need so many stages of filtration to purify your water? In actual fact, it depends! Some homes would benefit from a 5-stage system; some might need less, and others need more!
So, let’s take a look and see how a 5-stage reverse osmosis system works and if it might be the right one for you.
Contents
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Key Takeaways
- A 5-stage reverse osmosis system always has 5 stages of filtration, but there can be different configurations.
- The typical stages consist of pre-filters for carbon and sediment, the reverse osmosis membrane, and a carbon post-filter. There might also be additional types, like a UV purifier or remineralization filter.
How Does a 5-Stage Reverse Osmosis System Work?
How does a 5-stage reverse osmosis system work?
A 5-stage reverse osmosis system indicates that it has five stages of filtration that your water will pass through before being dispensed from the reverse osmosis faucet. Each step will work in synergy with the stage before. The stages typically include carbon and sediment pre-filtration, a reverse osmosis membrane, and a carbon post filter. Then, there may also be a unique added component, such as a UV purifier or remineralization filter.
The Filter Stages in a 5-Stage Reverse Osmosis System and What They Remove
A 5-stage RO system for water purification offers various filter combinations. These setups may include:
- Three pre-filters (two sediment filters and one carbon filter), followed by an RO membrane and a carbon post-filter.
- Three pre-filters (one sediment filter and two carbon filters), followed by an RO membrane and a carbon post-filter.
- Two pre-filters (one sediment filter and one carbon filter), followed by an RO membrane, a carbon post-filter, and a remineralization filter.
- Two pre-filters (one sediment filter and one carbon filter), followed by an RO membrane, a carbon post-filter, and a UV lamp.
1. Sediment Pre-Filter
By removing larger dirt and debris particles, this filter safeguards the RO membrane against clogging.
2. Carbon Pre-Filter
This filter aids in reducing chlorine and other impurities that lead to unpleasant tastes and odors in water. Besides, it is crucial to remove chlorine before it damages the reverse osmosis membrane.
3. Reverse Osmosis Membrane
The membrane removes various contaminants, including salts, heavy metals, microorganisms, microplastics, asbestos, and other chemicals and compounds.
4. Carbon Post-Filter
Removes any residual taste and odor in the water before drinking.
5. UV, Remineralization, and Other Specialized Filter Stages
An optional ultraviolet (UV) purifier is great if the feed water contains microorganisms like bacteria or cysts. This purification stage employs ultraviolet light to eliminate pathogens in the water by inhibiting their reproduction.
Adding a remineralization filter introduces an extra filtration stage where essential minerals like calcium and magnesium are replenished in the water for better taste and health. This results in a better flavor and an elevated pH.
Other more specialized filter stages can be used as well, such as iron filtration.
Other Components of a 5-Stage RO System
Naturally, your reverse osmosis system will comprise additional components apart from the filtration stages, namely:
Module
A centralized hub that links all components, enabling the smooth flow of water through the system.
Water Tank
A storage tank holds filtered water until required. Typically, countertop models do not include storage tanks, unlike under sink models.
Water Dispenser
The water dispenser offers convenient access to clean, purified water via a specialized faucet.
Drain Line and Saddle
This is for the complete removal of all wastewater produced by the reverse osmosis system.
Water Inlet
This serves as the origin of raw input water.
Automatic Shut-Off Valve
This valve suspends the system’s operation once the storage tank reaches its maximum capacity.
Check Valve
This valve obstructs any possible backflow of water from the storage tank or drain line.
Flow Restrictor
The flow restrictor controls wastewater flow, guaranteeing that the RO system maintains sufficient pressure for water to pass through the membrane.
How to Install and Maintain a 5-Stage RO System
There’s not really a difference when comparing 3, 4, or 5-stage reverse osmosis system when it comes to installation and maintenance. 5-stagers might just be a bit bigger than 3 or 4. And it may require a tad more work to maintain the different filter stages, but that’s about it.
Installation:
- Drill a hole in the countertop for faucet installation unless there is a spare one.
- Connect the drain saddle to the sink’s drain line.
- Under the sink, shut off the water supply and open the kitchen faucet. Install the feed valve and reconnect the tubing.
- Position the RO system module.
- Attach the storage tank by sealing the threaded port with Teflon tape and screwing on the connector.
- Connect all components with tubing.
- Install the filter elements into their respective housings.
- Turn on the feed water valve and inspect for leaks.
- Flush the system.
Further Reading:
Maintenance
- Close the water supply and storage tank valve.
- Depressurize the system by opening the RO faucet.
- Unscrew and remove all filters and the membrane from their housings. Use a filter or strap wrench if necessary.
- Ensure the O-rings are in good condition. If not, replace and lubricate.
- Add the new filter elements into their respective housings and reassemble each sump.
- Open the water supply and tank valve.
- Allow the system to flush by opening the RO faucet for a few minutes.
- Inspect for any leaks.
Is a Reverse Osmosis System with More Filter Stages Always Better?
The answer isn’t straightforward when choosing between a 3, 4, 5 or even more filter stages for a reverse osmosis system. The system’s effectiveness depends on the specific filter stages being used.
Adding extra filter stages to a system is sometimes done by manufacturers as a marketing tactic without necessarily improving filtration performance. The number of steps alone doesn’t guarantee better results. While additional stages can potentially enhance contaminant reduction, repeating the same filter media consecutively may not actually improve filtration. That is why it is vital to assess your water quality before determining which filtration stages you need and how many of them.
If you have any thoughts about the question, what is a 5-stage reverse osmosis system, please don’t hesitate to leave a comment below!
About the Author Alexandra Uta
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