Reverse Osmosis Systems





Reverse Osmosis is a process where water is demineralised using a semi-permeable membrane at high pressure. Your normal filtration units will only reduce certain contaminants such as silt, rust, chlorine and bacteria. Your reverse osmosis unit will purify your water up to 99.9% or 1 micron, thus removing other dissolved contaminants such as colloid, lead, mercury, germs and other metals.


It is essential that you maintain your home reverse osmosis unit to ensure you produce only the cleanest water and that you do not “poison” your drinking water. When the filter is not changed regularly, contaminants build up in the filter, it slows the flow of the water and most importantly, it feeds all the contaminants back into your drinking water! It is essential that, just like any machine, the unit be serviced regularly and filters changed every 3 to months to a year.


Depending on the source of the incoming water we recommend the following as a minimum requirement:

  • 6 to 12 Months change the melted spray, carbon block, granulated activated carbon filter and the taste and odour filters.
  • If you do this, you protect the membrane (most expensive part) which can then last for between 3 to 5 years.
  • It makes financial sense to rather change the cheaper filters more often as they protect the membrane and keep it free from contaminants.

Examples of  how the unit fits under the sink


  • Under counter home unit without pump
  • Under counter home unit with pump
  • Larger under counter units suitable for smaller guest houses
  • Larger capacity reverse osmosis systems available for large guest houses, offices and workshops




Stage 1 – Sediment Filter – Melted Spray

Removes particles such as silt and rust

The Sediment filter is usually the first stage in a water filtration system. It serves to remove visible dirt particles such as mud, rust, and sand from the water. This Melted-spray filter cartridge has a multi-layer structure and is self-bonded, thus not making use of a chemical binder. After passing through this filter, the water may appear to be clean. However, looks can be deceiving and most water contaminants are smaller than what our eyes can see. These contaminants may not be removable by the sole use of a sediment filter. Sediment filters are rated by a micron number. A micron is a unit of length that is equal to one millionth (10-6) of a meter. The most common sediment filters available are 1, 5, 10, 20, 30, 50 and 100um (micron) filters. The micron number refers to the largest dirt particle that will pass through the filter.


Stage 2 – Granular Active Carbon (GAC)

A filter with granular activated carbon (GAC) is a proven option to remove certain chemicals, particularly organic chemicals, from water. GAC filters also can be used to remove chemicals that give objectionable odours or tastes to water such as hydrogen sulphide (rotten eggs odour) or chlorine. Granular Active Carbon (also referred to as UDF by some manufacturers and retailers) is carbon that has been treated with oxygen to make it porous, but it has also been broken up into granules to further increase the surface area for chemical bondage to occur. The water passes through the GAC filter, allowing the organic materials and chlorine to effectively bond with the carbon molecules, thus removing these from the water.


Stage 3 – Carbon Filter (CTO) – Activated Carbon Block

Activated carbon is a form of carbon that has been treated with oxygen to make it very porous, allowing for a larger surface area for chemical reactions to occur. The carbon absorbs organic materials and Chlorine from the water with which comes into contact. The Activated Carbon Block is enclosed in a 5-micron filter to catch tiny carbon dust particles that may break off during the filtration.

Many carbons preferentially adsorb small molecules. Iodine number is the most fundamental parameter used to characterise activated carbon performance. It is a measure of activity level (higher number indicates a higher degree of activation) often reported in mg/g (typical range 300–1200 mg/g). It is a measure of the micro pore content of the activated carbon (0 to 20 Å, or up to 2 nm) by adsorption of iodine from solution. It is equivalent to the surface area of carbon between 900 and 1100 m2/g. So essentially the greater the Iodine Number Rating on an Activated Carbon Block, the more effectively the carbon will absorb things such as chlorine and organic molecules.


Stage 4 – Reverse Osmosis Membrane

Removes colloid, heavy metals, dissolvable solids, germs, bacteria and other harmful substances up to 1 micron


The Reverse Osmosis (RO) Membrane forms the heart of a Reverse Osmosis System. It consists of a semi-permeable membrane that allows water molecules to pass through, but captures 99.8% of all other particles in the water. The RO Membrane removes bacteria, viruses, minerals, heavy metals and pesticides from the water.   The RO Membranes typically have a life span of 2 to 3 years, however please note that this is completely dependent on the quality of the source water and the amount of usage.


Stage 5 – Post Activated Carbon Filter

Removes any odours and improves taste which occur as a result of the reverse osmosis membrane process by absorbing any organic molecules that come off the RO membrane.




Stage 6 – Mineral Injector

Re-introduces certain minerals

The mineral injector helps to replace some of the minerals lost during the Reverse Osmosis (RO) process. The Mineral injector is filled with small beads of mineral, as the water passes through the mineral injector small amounts of minerals breaks away from the beads and are carried with the water. Our mineral injectors insert traces of potassium, calcium, magnesium, germanium, and iron.

Potassium: Potassium is vitally important for the functioning of all the cells in the body, especially in the maintenance of neurons (nerve and brain cell). It is also an essential micronutrient that – together with sodium, chlorine, magnesium, and calcium – plays an important roll in maintaining the body’s electrolyte balance.

Calcium: All the muscles, bones and cells in the body require calcium to function. Calcium is also needed to facilitate the growth and maintenance of healthy bones and teeth.

Magnesium: Magnesium improves the function of the muscles, heart, and kidneys, by promoting the circulation of blood in the body. It helps to strengthen bones and teeth.

Germanium: Germanium is a plant-based mineral that has the property of being toxic to bacteria, but harmless to humans and animals. When ingested, it has also been found to stimulate metabolism of the body. It also has the ability to absorb heavy metals and impurities from water.

Iron: Iron is one of the main components of hemoglobin, the substance that enables your red blood cells to transport oxygen around your body. It is also part of myoglobin, which enables muscles to store oxygen that is used for cellular respiration.

  • The Mineral injector has a lifespan of 12 months (1 Year) and will need to be replaced.


Stage 7 – Alkaline Filter

Alkaline filter – Produces water with pH 8 and higher

One of the more complicated things to change and manage in water is pH. Our bodies want to maintain a pH of 7.8. So if we consume food or drink with a lower pH such as something very acidic (pH less than 7 is an acid) we have to use some of our reserves of calcium from our bones to maintain a steady pH level. Water often a relatively low pH such as 5 due to CO2 from the atmosphere being absorbed. The alkaline filter slowly dissolves minerals into the water that act as a buffer and increases the pH. It will vary with flow rate but the ideal is to get Reverse Osmosis (RO) water to a pH of over 8. This will eliminate the contribution of water to an acidic diet.