With 70% of the body made up of water, more and more consumers are becoming aware of the importance of healthy water, free from carcinogenic chemicals, including chlorine, as well as Fluoride and other contaminants.
This explosion in the water filter industry, comes with it a lot of misinformation as sellers look to enter the market with very little product knowledge. It is therefore up to the consumer to get an understanding of the different types of filtration to ensure they do not pay for what they do not need. Some sellers unfortunately make claims regarding heavy metal removal, copper, even fluoride, with a standard carbon block filter, which is totally misrepresented. The following is a brief overview to be able to decide what water filter best suits your needs.
There are a number of contaminants you may wish to remove from your drinking water.
Bacteria - Mainly a concern for tank water. Carbon allone is not recommend as it provides a warm, wet environment for bacteria to multiply. A quality Made in UK Ceramic / Carbon cartridge combination is recommended with a 0.2 micron rating to ensure all bacteria is removed from your water.
Some sellers recommend Ultra Violet filtration, however unless your water is clean, bacteria are not targeted.
NOTE: Town Water Supplies that are disinfected with chlorine do not have bacteria present.
Heavy Metals (Copper) - Copper cannot be effectively removed by carbon filtration alone and requires either reverse osmosis or ion exchange to remove.
Salt (Desalination) - This require a 'high pressure' osmosis process. Recommend searching for desalination for requirements. A standard reverse osmosis will not remove the high levels of salts etc.
Hardness (Calcium & Magnesium) - This requires a cation resin or polyphosphate media, which will eliminate these contaminants. For reverse osmosis units, a hardness removal cartridge should be incorporated into your pre filters. However, if calcium levels are particularly high in your area (especially some areas of WA, NT etc), we strongly advise having your water tested by a lab to determine if a water softener is required. Domestic water filters may otherwise clog up very quickly and require regular maintenance which could become very costly.
This is minimum filtration with the quality of the water determined by the micron rating of the carbon cartridge. There is also an absolute and nominal micron rating, however many online sellers use only a nominal rating. However, an absolute rating is a far more accurate measurement, and as such, we try to always specify this method. NB: A 1 micron absolute is the equivalent to a 0.5 micron nominal.
With the health scare associated with the presence of the Giardia parasite in Sydney water in the late 90’s, many Australian companies should be incorporating a 1.0 micron absolute (or 0.5 micron nominal) cartridges to ensure Giardia removal. Lead is also another element removed by quality (Made in USA) 1.0 micron absolute carbon block cartridges.
Any form of single or carbon filtration should incorporate a minimum of 1.0 absolute micron for the carbon component. Twin systems also include a 1 micron pre filter to remove sediment etc.
Coconut carbon as the source of carbon as against coal based carbon is also available and offers a more natural source of carbon to eliminate the leaching of phosphates, associated with coal based carbon.
5 micron or higher micron 'pre carbon' cartridges are used in Reverse Osmosis for Chlorine removal and to ensure flow rate is not compromised, essential for membrane performance.
NOTE: Carbon is not recommended for use on unchlorinated water as it provides a wet, warm environment for bacteria to grow. A silver carbon can be used when taste and water discolouration from leaves etc. is a problem, the silver inhibiting the bacteria to multiply. A quality Made in UK ceramic carbon filtration cartridge is recommended for unchlorinated water.
Some sellers promote the removal of heavy metals using a carbon block cartridge. Unfortunately this should be viewed as questionable as heavy metals, apart from lead, cannot be removed by absorption and require either membrane (reverse osmosis) or ion exchange (UltraCarb) technology.
Available as Ceramic only when water flow is an issue or a Ceramic / Carbon cartridges with a ceramic outer skin and a carbon middle are used mainly for bacteria removal as well as the removal of copper and some heavy metals. The ceramic can be scrubbed to ensure cartridge life. The inclusion of ion exchange within the cartridges for the removal of heavy metals, including Copper is an alternative to Reverse Osmosis when copper in pipes is a concern.
The special blend of carbon in the centre of the Doulton Ultra Carb will remove Algae, Aluminium, Ammonia, Cadmium, Chlorine, Chloroform, Cryptosporidium, Giardia, Heavy Metals, Lead, Mercury, Pesticides and Herbicides, Rust and Dirt.
The incorporation of silver locked within the ceramic structure inhibits the growth of bacteria and gives the cartridge enhanced bacteriostatic and self-sterilising properties
POSITIVES - An alternative to Ultra Violet for the removal of bacteria from tank water. Effective removal of copper when this is a health concern
NEGATIVES - Over time cam restrict water flow and thus needs regular maintenance.
Water is first heated to boiling. The water vapour rises to a condenser where cooling water lowers the temperature so the vapour is condensed, collected and stored.
POSITIVES - Removes most contaminants without loss of water.
NEGATIVES - This process requires a lot of time and energy, more importantly the water has zero minerals, which makes it unsuitable for drinking. Taste is also FLAT.
This is a mixture of negative and positively charged resin beads that bond with minerals and hold them within the cartridge, removing them from the drinking water. This method was used in the early nineties as an option to remove fluoride and heavy metals, however it has limitations in that it becomes saturated very quickly and can dump contaminants back into the water supply. The resin beads also tend to sweat and can impart a fishy taste to water.
Their capacity is very limited and expensive, with most standard cartridges removing contaminants for approx. 800 litres.
POSITIVES – When used as a final polish with reverse osmosis to remove the very small amount of residual minerals for those consumers wanting total mineral removal. As the reverse osmosis has done most of the work removing minerals, their capacity is extended.
NEGATIVES - Expensive to use with limited capacity.
This is by far the most economical water filtration method. No longer do we have waste ratios of 1 litres of pure water to 4 litres of waste water. Efficient membranes have made this an efficient removal of minerals for those consumers wanting to take control of the quality of their drinking water.
A 4 stage reverse osmosis is standard, and any additional stage should only be considered if water is high in calcium, when a cation resin cartridge may be recommended as membranes can be damaged by hard water.
Configuration is usually a sediment and chlorine pre filter to ensure clean water prior to membrane stage. The membrane is the main component of the reverse osmosis and provides ultra fine membrane that separate the water molecules to pure and waste water. Reverse Osmosis process.
Some sellers recommend 5 – 6 stages with additional chlorine pre filters, which is not necessary unless in high chlorine areas. These additional stages in many cases are profit derived to to increase your yearly replacement cartridge needs. Any additional stages would involved adding minerals back into the water.
Note: The Purestream range of reverse osmosis all include a membrane flushing mode, designed by Purestream late 90’s and copied by some water filter sellers. This allows water to be flushed down the membrane to dislodge any build up of crystalisation or other contaminants and ensures purity of membrane. This is done once or twice a year by simply turning a switch.
POSITIVES – Efficient method of removing all contaminants, including bacteria.
NEGATIVES - Produces slightly acidic water 6.4 pH. Slow production of water.
REMINERALISING & ALKALISING
While this is not a filtration component, enhancing the health benefits of water has been the main push in the development of water filtration. The discovery that water has memory and the ability to restructure water to harness incredible health benefits from natural ore mineral rocks has reinvented water filtration.
Water is no longer just wet and Purestream’s commitment to Adding Wellness to Water has seen the company at the forefront of health giving water.