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What is Reverse Osmosis Water?

Home reverse osmosis water filtration systems have never been as well-priced as they are right now! This is the ideal time for you to purchase one if you are interested in pure drinking water for home. Understandably, you may have a lot of questions that need answering before you commit to anything. This FAQ is here to help.

Reverse Osmosis Water Filtration System how does it work?

The term reverse osmosis refers to a technology that was first developed by submariners to convert sea water into fresh drinking water. The water is forced through a membrane the outer layer of which is very permeable to water but provides a high rejection of undesired materials such as Fluoride! The water is filtered to microscopic levels, the pore on the membrane is less than 5 Angstrom which does not mean a great deal to most people; to put it in perspective if you imagine that a square foot of membrane is equivalent to the Pacific ocean a pore in a reverse osmosis membrane would then be equivalent to a 5 cent piece.

A friend of mine told me that Reverse Osmosis will not filter out Chlorine is this true?

Technically correct, in fact if a TFC membrane is used the chlorine will actually attack the membrane and destroy it. Of course that is why carbon filtration is used to remove the chlorine before it comes into contact with the membrane, so yes the membrane does not treat for chlorine however it is not a valid argument and is only used to muddy the waters.

My friend also told me that Reverse Osmosis Systems waste a lot of water is this true?

Yes Reverse Osmosis Systems do have to send water to drain, although it depends what you define as a lot of water. In our low waste units, with optimal conditions we can reduce that pure water to waste water ratio to about 1:1 that is 1 litre of water to drain for every litre of pure water. There are some factors which will affect this, the quality of the incoming water, the temperature of the incoming water and the pressure of the incoming water will all have a significant influence in the operation of any reverse osmosis system.

Is the water produced by reverse osmosis process acidic?

The water produced by reverse osmosis process is very pure and by that very fact it will absorb carbon dioxide from the air quite easily, in nearly every case that we have tested the ph of the water is slightly acidic, we do have alkaline post filters which will re balance the ph.

Does Reverse Osmosis remove beneficial minerals from the water?

The answer to this is yes if you believe that water contains beneficial minerals then there is no doubt that reverse osmosis will remove them along with Fluoride and any other organic or in -organic chemical. Please consider this information available from The World Health Organisation:

“A WHO Expert Workshop on nutritional components of drinking-water was held in November 2003 in Rome. The result of the workshop was a report on “Nutrient minerals in drinking water and the potential health consequences of long-term consumption of demineralised and re-mineralised and altered mineral content drinking waters.” The workshop concluded that drinking-water was generally not a significant contributor to daily dietary nutrition but could be important in cases of dietary insufficiency.”

I can buy a 75 gallon a day membrane for the same price as a 24 gallon per day membrane wouldn’t I be better with the higher producing membrane?

With reverse osmosis membranes, more is not better. The membrane requires to be “used” as it is designed as it relies heavily on water passing through it to flush away contaminants. So answer is decide how much water you want to use and buy a membrane to suit.

I want to upgrade my current system and use a higher producing membrane is this an easy process?

Yes and No, if you change from say a 24 gallon to a 50 gallon per day membrane it will fit inside your reverse osmosis housing however every system has a flow restrictor going to the drain and this varies according to the production capacity of the membrane, if you are in doubt call us. If you have the incorrect flow restrictor the membrane can foul easier or you may have an excessive amount of water going to drain. We can also provide advice on how to set up a simple flushing valve which will enable you to flush the membrane manually if required.

What is the difference between a TFC membrane and a CTA membrane?

A TFC (Thin Film Composite) is the membrane most commonly used in reverse osmosis for home in Australia. It is very susceptible to damage from chlorine however it has the advantages of providing a high rejection of contaminants along with a great longevity if a carbon pre filter is utilised.

A CTA (Cellulose Tri Acetate) membrane is less common, this membrane is however resistant to chlorine.

How much Water can I expect from my Reverse Osmosis System?

Reverse Osmosis membranes produce different amounts of water per day depending on how they are manufactured. We supply membranes that produce 24, 36, 50 and 75 gallons of water per day which is approximately 90, 135, 190 and 280 litres per day. The production rate will also be affected by water temperature, length of run from unit to holding tank, incoming water quality and the pressure of the incoming water.

How can I tell if my Reverse Osmosis System is working properly?

This can be tested easily using a TDS (total dissolved solids) meter, water coming immediately out of the reverse osmosis membrane will be around 0 or 2. You can also test your production rate by turning the valve on your tank off and measuring how many minutes it takes to fill a litre jug from your pure water tap.

What contaminants are removed from the water by a Reverse Osmosis System?








Arsenic 98% Herbicides Over 98%
Barium 95% Pesticides Over 98%
Cadmium 95% DDT Over 98%
Calcium 98% Endrin Over 98%
Chloride 95% Lindane Over 98%
Chromium III 98% Aldrin Over 98%
Copper 98% Benzene Over 98%
Fluoride 95% VOCs Over 98%
Iron 98% Adrazin Over 98%
Lead 98% Fluorathene Over 98%
Magnesium 98% Phenol Over 98%
Manganese 98% Trihalomethanes Over 98%
Mercury II 85% Toxaphene Over 98%
Nitrate 90% Dichloromethane Over 98%
Potassium 95% Chloroform Over 98%
Selenium IV 95% Trichlorethylene Over 98%
Silver 98% Perchlorethylene Over 98%
Sodium 95% Tannic Acids Over 98%
Strontium 98% Methoxychlor Over 98%
Sulfate 98% PCB Over 98%
Zinc 98%
Total Dissolved Solids 95%
Asbestos 99%