Reverse osmosis systems are remarkably effective at removing viruses and bacteria from water, making them one of the most thorough water purification solutions available. In fact, these systems can remove an impressive range of contaminants, including fluoride, chlorine, lead, salt, sodium, copper, calcium, magnesium, and phosphorus.
Reverse osmosis filters offer exceptional purification capabilities, working as an efficient solution that delivers clean water suitable for a wide range of applications from commercial and industrial properties to homes, aquariums, restaurants and more.
In this comprehensive guide, we’ll explore everything you should know about reverse osmosis water systems, from their working principles to maintenance requirements, helping you to understand whether this powerful filtration technology is the right choice for your needs.
How Reverse Osmosis Water Filters Work
If you need to eliminate problem contaminants from your water, then reverse osmosis filters can help to remove pesticides, viruses, salt, microplastics, heavy metals, fluoride, sediment, bacteria, chlorine and pollutants, for clean, safe, pure water.
The fundamental principle behind reverse osmosis filtration involves forcing water through a semi-permeable membrane under pressure. Unlike natural osmosis, where water flows from a less concentrated solution to a more concentrated one, reverse osmosis applies external pressure to reverse this natural flow. This pressure-driven process effectively separates water molecules from contaminants.
A typical reverse osmosis system consists of multiple filtration stages working together to produce clean drinking water. The heart of any reverse osmosis water filter is the RO membrane – a thin-film composite material with microscopic pores approximately 0.0001 microns in size. This remarkable membrane allows only water molecules to pass through while blocking up to 99% of dissolved solids.
Most residential reverse osmosis filters feature three to five distinct filtration stages. In a standard three-stage system, water first passes through a sediment pre filter that removes particles as small as 5 microns, including dust, rust, and mud. The second stage typically contains a carbon filter that eliminates chlorine, foul tastes, and odours. Finally, water reaches the crucial RO membrane that removes dissolved solids, including radium, lead, and arsenic.
More advanced four and five-stage systems incorporate additional filtration elements. These might include a second carbon filter for “polishing” the water or a remineralisation cartridge that adds beneficial minerals back into the purified water. Consequently, these multi-stage systems provide more comprehensive filtration and better-tasting water.
Choosing the Right Reverse Osmosis Water System for Your Needs
Selecting an appropriate reverse osmosis water system requires careful consideration of several factors that match your specific needs and requirements. Firstly, you’ll need to decide between traditional tank-based systems and modern tankless options.
Tank vs. Tankless Systems: Tank-based RO systems store filtered water in a sealed pressure tank, providing immediate access to purified water. These systems typically cost less initially than tankless alternatives and deliver faster output at the dedicated faucet. Nevertheless, they require twice the space under your sink and may develop bacterial growth in the storage tank over time.
Tankless RO systems, despite being more expensive upfront, offer several advantages. They need only a fraction of under-sink space, produce nearly unlimited water at a consistent rate, and generate much less wastewater. Additionally, tankless systems are generally easier to maintain, with filter changes taking seconds rather than minutes.
System Capacity: Reverse osmosis systems are rated in gallons per day (GPD). For residential use, a 50 GPD-rated system is typically recommended. To put this in perspective:
- 50 GPD equates to approximately 0.13 litres per minute
- 100 GPD delivers about 0.26 litres per minute
Space Requirements: A standard 3-4 stage RO system requires approximately 14 inches in width, 7 inches in depth, and 14-17 inches in height, plus space for a storage tank that’s 16 inches tall and 11 inches in diameter. Notably, the RO unit and storage tank can be positioned in opposite corners under your sink.
Water Pressure Considerations: Before purchasing, ensure your property has normal water pressure between 2.7 bar (40 psi) and 5.8 bar (84 psi). Low pressure may require a booster pump, especially for tankless systems.
Maintenance of Reverse Osmosis Systems
Proper maintenance of reverse osmosis water filters is essential for ensuring optimal performance and longevity, with well-maintained systems potentially lasting 10-15 years. Setting up and caring for these systems involves several key considerations to keep your water pure and your system running efficiently.
Filter Replacement Schedule
Timely replacement of filters is crucial for maintaining water quality:
- Sediment pre filter: 6-12 months
- Carbon pre filter: 6-12 months
- RO membrane: 2-5 years (2-4 years for hard water, 5-7 years for soft water)
- Polishing/post filters: 12 months
Neglecting filter replacement schedules can damage your system and decrease water production. Moreover, old filters lose filtration power as they become clogged with contaminants that may leach back into your water.
Regular Maintenance Tasks
In addition to philtre replacement, other maintenance tasks include:
- Sanitising the system annually to prevent bacterial buildup
- Draining the storage tank at least once every two weeks to maintain proper pressure and keep water fresh
- Checking tank pressure regularly (optimal pressure is 5-7 psi when empty)
A well-maintained reverse osmosis system can serve your property effectively for years while removing nearly all harmful contaminants from your water supply. Whether you choose a traditional tank-based system or opt for a modern tankless solution, understanding the maintenance requirements helps ensure optimal performance throughout the system’s lifespan.