Reverse Osmosis Water Filters

Of all the methods to purify water, reverse osmosis is the most advanced and effective. It was developed more than 50 years ago by scientists at the University of California, Los Angeles (UCLA). Since then, both private and public sectors have invested many millions in developing and refining reverse osmosis techniques.

After passing through usually two speciality pre-filters, polluted water is then forced by water pressure against a semi-permeable RO membrane. Purified water molecules easily pass through the membrane while pollutants, typically being larger than the pores, cannot pass through and are washed away. In effect, the membrane divides the purified water allowing this to be stored in a tank ready for use and dumps the unpurified water as waste.

The ratio of waste to purified water depends on the brand, quality, and type of membrane used in your reverse osmosis system.

While some membranes have a waste ratio of 3:1 (three litres of waste per one litre of purified water) our Aquakleen Safety Seal Reverse Osmosis System now has a 1:1 ratio membrane, making this reverse osmosis system and water dispenser one of the best in the world.

Yes. As the membrane is .0005 microns very little can get through, meaning that minerals are also stripped out. While we shouldn’t rely only on drinking water for essential minerals in our diet, there is a simple solution if you are concerned about this. You can add a mineraliser cartridge after the tank to put the minerals back in after the water has been purified. 

While most reverse osmosis systems are designed to be compact and mounted out of the way, you also need to consider the size of the water storage tank. These come in many sizes, and the most common residential size of the tank is 8 litres and is not much larger than a small pot.

Our Aquakleen Reverse Osmosis System is 420mm high x 325mm wide x 115mm deep, and the standard 8 litre tank size is 317mm high x 203mm in diameter. The 12 litre tank is 367mm high x 243mm in diameter. 

Each filter in your standard reverse osmosis system plays an integral part in the purification process in creating the best reverse osmosis water. Most reverse osmosis systems use four or five filters, and each of these has a special role:

• Filter 1: Sediment – initial filter to remove larger particles.
• Filter 2: Carbon – removes chlorine before the water reaches the membrane as chlorine damages it.
• Filter 3: Membrane – reverses the natural water flow so only purified water molecules can pass through, and polluted water is dumped as waste.
• Filter 4: Carbon – polishes the water as a final stage to improve the taste.
• Filter 5: Optional mineraliser – adds the minerals back into the purified water before dispensing from your tap.

When the water reaches the membrane, it is forced in the reverse direction of normal osmosis from a larger concentration to a lesser concentration. The lesser concentration is 'purified' and the larger concentration is waste. The natural water flow is reversed, hence the term reverse osmosis. This filter is the best option for water filtration, desalination of seawater, and kidney dialysis machines.

The brand of reverse osmosis system you purchase will determine how easy it is to change the filters. Our Aquakleen Reverse Osmosis Safety Seal system makes it very easy to change your filtered water faucet as they have a thread and simply screw in and out. It's as easy as changing a light bulb and saves you the cost of having a service technician do it for you.

When you leave your reverse osmosis out of use for a period of time, you must consider two main things: the filters and the water storage tank.

If you are going away for a long period of time, we recommend you run your sink water for 5 minutes to flush your filters through and then remove them, and store them in an airtight ziplock back in the back of your fridge. This will prevent your filters from growing bacteria and drying out when not in use.

You should also empty your tank before you leave. When you return and put your filters back in, flush them through and fill up your tank, then empty your tank again. Once you fill it up for the second time, you’ll be ready to go.

If you’re worried about any potential bacteria build up in your tank, you can always dissolve a tablet form of steriliser (like the tablets used to sterilise baby bottles) which are available from most supermarkets.

As each sediment filter has a different role, they need changing at different times. Effectively, the cleaner the water source is when it reaches each filter, the longer that filter will last. We recommend the following filter change frequencies to ensure healthy drinking water:

• Filter 1: Sediment – 6 monthly
• Filter 2: Pre-carbon – 12 monthly
• Filter 3: Membrane – 4 yearly
• Filter 4: Post carbon – 2 yearly
• Filter 5: Optional mineraliser – 2 yearly