All You Need to Know About RO Filters


Reverse osmosis water filters are used in households and commercial settings, where a constant supply of high purity water is needed. Most reverse osmosis filters are advanced multi-stage filtration units that can be used in the removal of a variety of contaminants.

Reverse osmosis filters are pressure-based systems, which means that certain water pressure requirements must be met for the optimal operation of reverse osmosis systems.

With very few exceptions, reverse osmosis water filter systems rely on incoming water pressure, which can be increased with a help of a booster pump if it’s below the required threshold.

In our guide to reverse osmosis water filters, we discuss all that you need to know about reverse osmosis filtration before you invest in an RO filter for your home.


What to Expect from Reverse Osmosis Filters in 2018

Reverse osmosis filtration is constantly evolving, and new changes appear every year. Here’s some of the changes to RO filters that you can enjoy in 2018:


  • Direct flow, tank-free models: reverse osmosis filters have been made more efficient by the emergence of direct flow, tankless reverse osmosis filters like the BMB reverse osmosis filter lines, which are designed to minimise water waste, and save more space;
  • Water monitoring: the newest RO filters feature water usage tracking, water temperature tracking, system error alert displaying, filter lifetime monitoring, etc.;
  • Low-maintenance: RO filters have become low-maintenance units thanks to the optimisation of filter cartridge service life. Now filters can last up to 12 or even 36 months before needing replacement, and in some RO systems like the BMB-20 +Alkaline +Detox Pumped Quick Change 6 Stage Reverse Osmosis System have filters that are all replaceable every 12 months;
  • Antibacterial filters: many RO systems now feature antibacterial filters. Despite prolonged filter lifetime, bacterial grow-through may shorten the service life of your filters, but adding bacteriostatic filter media will ensure that bacterial growth is inhibited, and the service life of your cartridges is prolonged. Cartridges are often infused with silver or zinc nanoparticles to inhibit bacterial growth;
  • More compact models: despite the growing number of filtration stages, many reverse osmosis models have now become more compact and easier to fit inside your kitchen cupboard. Tankless reverse osmosis filters have also contributed to RO filters becoming more compact in size;
  • Alkaline filters/Detox filters/Re-mineraliser filters: because reverse osmosis removes healthy minerals from water, many RO systems now come with alkaline filters, detox filters, or re-mineraliser filters, which all serve the same purpose — optimising water for better taste and wholesomeness. These filter cartridges add trace amounts of healthy minerals back into water to replenish lost minerals, and raise the pH of water, so it’s no longer acidic;
  • Quick-Change Filters: quick-change filters have become the staple of low-maintenance filters. Filter cartridges designed with the QCF technology are easy to replace, there’s no contact with filter material, and their replacement can be carried about without the intervention of a plumber.


Types of Reverse Osmosis Water Filters

Reverse osmosis filters have always featured a reverse osmosis tank, where filtered water was stored before consumption. Recent changes in the reverse osmosis landscape, however, have brought new changes to traditional reverse osmosis systems, by borrowing from the immediateness of typical undersink water filters.


Traditional Reverse Osmosis Filters

Traditional reverse osmosis water filters feature a reverse osmosis membrane, several pre- and post-filters, and a reverse osmosis tank, where filtered water is stored. When the RO tank becomes full, the filtration process shuts down automatically.

Reverse osmosis systems produce wastewater, which – depending on the RO system – can be circulated back into the system, put to some other use in your household (e.g. irrigation, flushing toilets, used in decorative fountains, etc.), or can be left to go to drain.


Tank-Free or Direct Flow Reverse Osmosis Filters

Tank-free or direct flow reverse osmosis filters no longer store reverse osmosis water, instead they deliver filtered water for immediate consumption.

These systems are equipped with at least two reverse osmosis membranes, and just like traditional models, they rely on water pressure to filter out contaminants from tap water.

With tankless reverse osmosis filters, filtered water is only produced when needed, and it’s available immediately when you turn on the tap.


Which is Better?

Both systems have their advantages and disadvantages. A common disadvantage is the fact that both systems will still produce wastewater, although many direct flow systems will claim to minimise wastewater production.

While tankless models save more space, and are more convenient than traditional RO models, they are usually more expensive, and RO membrane replacement costs are higher.

Even so, many will prefer the highly polished water produced by tankless systems, and the immediately available RO purified water.


What to Look for in a Reverse Osmosis Water Filter System?

Reverse osmosis filters are suitable for any commercial or residential use, where highly purified water is needed. Whether you want RO water in your dental surgery or as an under-sink filter in your home, there are many RO filters options available.

Here’s what you should look for in a reverse osmosis water filter:


  • Water Pressure Requirements:


Since reverse osmosis systems are highly dependent on incoming water pressure, check if your water pressure meets the requirements of the RO filter you want to buy. RO systems simply don’t operate properly in low-pressure environments.

If your water pressure is slightly lower, go for a pumped RO system that features a booster pump that can improve your water pressure. If you’re water pressure if off by a huge margin, a reverse osmosis system is not a good option for you.


  • Filtration Stages:


RO filters have at least 4 filter cartridges including the RO membrane. If your tap water quality is problematic, an RO filter with more filtration stages may be a better fit for you, but make sure you don’t go overboard as you may be required to compromise on flow rates.

If your tap water is acidic, an RO filter may make it even more acidic, so consider a reverse osmosis water filter that features an alkaline or re-mineraliser filter cartridge that will replenish the minerals lost in the filtration process.


  • Filtered Water Output:


Consider your daily water consumption needs and see if the RO filter you’re planning to purchase can meet those requirements.


  • Wastewater:


The less water your RO system wastes, the better. If you’re not sure about how much wastewater is produced by the filter you want to purchase, get in touch with your vendor.


  • Specialised RO Filters:


If you need an RO filter for a special purpose, e.g. for a dental surgery, make sure to buy a filter that is designed especially for dental surgeries. This is important because filters for residential use may not meet the certifications required for that special purpose. Same goes for reverse osmosis filters that you may want to use in the food and catering industry.


  • Maintenance Requirements:


If you don’t know much about plumbing, find an RO filter that’s easy to maintain. Reverse osmosis filters with quick-change filter technology are the easiest to replace, so find an RO filter that features QCFT filter cartridges.


Next in our reverse osmosis filter guide, we’re going to discuss about two filter lines – the BMB and the Ecosoft, both available for purchase in our webshop.


The BMB Reverse Osmosis Filter Line

BMB reverse osmosis systems are available in multiple models — tank-free or direct flow models, traditional reverse osmosis filters with reverse osmosis tanks, pumped or non-pumped versions, etc.


Common features of the BMB reverse osmosis filter line include:


  • Compact size, fits nicely under the kitchen sink;
  • Filter cartridges that feature the Quick-Change Filter Technology for easy and low-cost maintenance;
  • Multiple filtration stages;
  • Small footprint;
  • Antibacterial filter cartridges for longer service life;
  • At least 12 month filter lifetime.


For the purposes of this article, we’ve chosen to discuss about two BMB reverse osmosis filters, the BMB Nano Quick Change Compact Reverse Osmosis System, an affordable and compact BMB RO filter, and the BMB-30 NOVA PRO Direct Flow 9-Stage Reverse Osmosis System, the ultimate in high-end direct flow reverse osmosis filtration.


 BMB Nano Quick Change Compact Reverse Osmosis System

The BMB Nano is an affordable, space-saving reverse osmosis filter that features a reverse osmosis tank, and 4 nano-technology filters.

The system is easy to assemble due to its “Plug & Play” components, and features the following filter cartridges:


  • 5-micron antibacterial sediment filter infused with Zinc nanoparticles;
  • 1-micron antibacterial sediment filter with coconut shell carbon;
  • thin-film composite semi-permeable membrane with 0.1 nano-meter sized pores;
  • And a coconut shell carbon filter with pH stabiliser effects.


This filter was designed to be used for residential purposes in households with a daily filtered water consumption of 20 to 50 litres. The system is installed under the kitchen sink with a secondary filtered water tap placed on the kitchen sink. Alternatively, the BMB Nano can be used with a 3-way kitchen tap that eliminates the need for a secondary tap.

The system removes hundreds of tap water contaminants including 99.99% of microorganisms.


BMB-30 NOVA PRO Direct Flow 9-Stage Reverse Osmosis System

As one of the most technologically advanced RO water filter systems currently on the market, the BMB-30 is a direct flow, tankless reverse osmosis system that features as many as 9 stages of filtration.

The system was designed both for residential and commercial use, producing up to 1000 litres of filtered water per day. Like all BMB RO filters, this system comes with plug & play components, and QCFT filter cartridges in the following configuration:


  • 5-micron antibacterial sediment filter infused with Zinc nanoparticles for antibacterial properties;
  • Coconut shell carbon pre-filter with antibacterial properties;
  • 1-micron sediment filter with antibacterial properties;
  • 2 x 400 GPD reverse osmosis membranes;
  • Mineral filter, Detox Filter, Oxygen Filter, and Alkaline filter.


The pre- and post-filters have a service life of 12 months, while the reverse osmosis membranes are replaceable every 36 months.

The Nova Pro is a Direct Flow system, meaning that is comes without a reverse osmosis tank, and features a digital controller and water tracking system that tracks the water temperature, water consumption, displays system errors and filter life.

The system also features automatic reverse flush of reverse osmosis membranes for optimum water quality. This BMB filter produces delicious pH optimised alkaline water.


The Ecosoft Reverse Osmosis Filter Line

The Ecosoft filters are traditional reverse osmosis filters that stand out thanks to their affordability, ease of use, and low running costs. The Ecosoft RO filters available at are traditional models that feature RO storage tanks, and are available in 5 or 6-stage versions with or without a booster pump.

Common features of Ecosoft reverse osmosis filters:


  • Affordable RO system for residential or commercial purposes;
  • DIY installation and maintenance;
  • Low running costs (GBP50-60/year);
  • High contaminant removal capacity.


Ecosoft 5 Stage Non-Pumped Reverse Osmosis System

The 5-stage Ecosoft system is an affordably priced, low-maintenance reverse system suitable for residential use. The system is easy to install at a single point of use, featuring 5 filtration stages as follows:


  • 5-micron sediment pre-filter;
  • 5-micron carbon block filter;
  • 1-micron sediment pre-filter;
  • Dow Filmtec 50 GPD Membrane;
  • And an inline activated carbon filter.

Pre-filters are replaced every 3 to 6 months, the post-filter is replaced every 6 to 12 months, while the RO membrane lasts up to 24 months. These filters have a high contaminant removal capacity removing the most common tap water contaminants like chlorine, heavy metals, bacteria, VOCs, fluoride, and many more.

The filter kit includes a chrome designer faucet, installed as a secondary tap on your sink, however, you can upgrade to a 3-way kitchen tap, and replace your existing tap.


Ecosoft 6-Stage Pumped Reverse Osmosis System with Alkaline Filter

This 6-stage Ecosoft system is a one-up from the 5-stage model thanks to the extra filtration stage and the booster pump included with the filter kit.

The re-mineraliser filter included with this system adds ionised calcium, magnesium, potassium to water to replenish lost minerals, and produce delicious alkaline water. The re-mineraliser last 6 to 12 months.

Other than the alkaline filter, the system also includes a booster pump, which makes sure that water pressure is at optimal level.


How to Care for Your RO Water Filter?

Reverse osmosis filters are easy to maintain; however, periodic filter replacement is crucial for the optimal functioning of these filters.

In addition to the reverse osmosis membrane, a reverse osmosis water filter is made up of several pre- and post-filters that make the system a complete filtration unit.

In a traditional RO water filter, pre-filters have the shortest lifespans due to their role in the filtration process. Their role is to remove sediments that may clog the RO membrane and to protect it from chemical disinfectants and other corrosive water ingredients.

Thus, these filters must be replaced more often than other filter cartridges in the system. Depending on the quality of your tap water and usage, these filters last anywhere from 2 to 12 months.

The reverse osmosis membrane lasts the longest in a system, usually 12 to 36 months, depending on the model and brand.

Post-filters in an RO system are polishing filters, meaning that they remove any leftover contaminants, and they improve the taste and odour of water, or add minerals to it. These filters have a longer service life than pre-filters, and usually last 6 to 24 months.

The tricky thing about reverse osmosis filter maintenance is to remember to replace the filters at the required intervals bearing in mind that each filter category may have different lifespans.

Some filter systems like the BMB Nano feature filter cartridges that all have the same service life, so if you have trouble keeping track of different replacement dates, you should choose an RO filter with filter cartridges that are all replaceable at the same time.

If your reverse osmosis filter comes with a storage tank, we recommend sanitising it at least once a year or every other year. Over time, debris and dirt can build up in the storage tank especially if your RO water is more acidic.

To clean the storage tank, you can buy special water filter sanitising kits, or use a home-made solution of white vinegar and water. Make sure you use non-toxic or organic sanitising solutions, and flush your RO system after cleaning to avoid any issues.

Final Thoughts

Reverse osmosis systems are complex filtration units that remove bacteria, chemicals, chlorine, chemical disinfectant by-products, VOCs, heavy metals, minerals, herbicides, pesticides, fluoride, nitrates, nitrites, sodium, asbestos, arsenic, and more.

The strength of reverse osmosis filters lies in the combined filtration efficiency of the pre- and post-filters that make up the RO system together with the RO membrane.

Whether you want highly polished water in your kitchen or in your dental surgery, an RO system can be a catch-all system to deal with a wide range of water impurities.

With so many reverse osmosis filter options available – direct flow, RO systems with QCFT, RO water filters with or without booster pumps, etc. – you’re sure to find the RO filter most suitable for your needs.


Shares 0