There are several different types of water filtration systems for domestic use. These are made from varying materials and designs, and may either be whole house or drinking water filters. They consist of carbon, sand, ceramic, reverse osmosis, among many others.
Selecting the best water filter is usually not a straightforward matter so it’s always good to consult with an expert in the field, as there are many varieties available. However, filtration is a simple, healthy, economic and more sustainable method of water purification than any other.
Significance of the filtration flow rate
One crucial factor to consider when buying a water filter is the filtration flow rate. This will greatly determine the effectiveness of the entire filtration system, and the type of contaminant that is eliminated. A slower flow rate is better for greater purification, as compared to a faster flow rate.
Whole house filters are designed to allow greater flow rates. This is to provide sufficient clean water for the entire home. They are effective at eliminating disinfectants like chlorine and other chemicals, rather than bacteria, cysts or viruses. Drinking water filters on the other hand, have much slower flow rates. This ensures a much better reduction of chemicals and heavy metals such as ammonia, copper, fluoride, lead and other toxins.
Benefits of a slow filtration flow rate
Most water filters have a porous layer of granular material like sand or carbon, or micro-strainers such as those in stainless steel filters. Water is sieved and purified as it passes between these tiny granules measuring fractions of a millimetre. Furthermore, the filter particles are negatively charged, so as to attract and trap positively charged toxins.
A filter with a slower filtration flow rate is advantageous in the following ways:
- The slower flow rate enables greater interaction between negatively charged filter particles and positively charged toxins. This maximizes the amount of toxins that can be trapped and filtered out.
- The slower flow allows better formation and less agitation of the layer of trapped bacteria on top of a slow sand filter, which kills other microorganisms in the water.
- A slow flow rate requires the filter to have finer granules than a higher filtration flow rate. Finer granules are more effective at filtering tiny contaminants such as bacteria and chemicals. This is what makes drinking water filters better than whole house filters.
How to decrease the filtration flow rate
The filtration flow rate in any filter can be decreased. This increases the effectiveness of filtration, and the range of contaminants that can be removed.
This can be done in the following ways:
- Finer granules: Filters with much finer carbon or sand particles slow down the filtration flow rate, making them more efficient at eliminating contaminants.
- Narrow tubes: These restrict the flow of water through the system, thereby reducing the filtration flow rate.
- Sub-micron cartridges: These use microscopic pores measuring 0.5 microns, which considerably slows the filtration rate.
Aside from the construction of the filters themselves, it is also possible to slow the water flow rate entering the filter with the use of flow restrictors and pressure limiting devices on the water supply lines. In some cases it can be as simple as turning the controlling tap so that is nearly in the off position.
The preferred water filtration flow rate will depend on the type of cartridge being used. Domestic carbon cartridges and slow sand filters have flow rates of up to 1-2 litres per minute, depending on the size of the filter.
Depending on which type of filter you choose, the filtration flow rate will greatly determine how efficient the system will be at delivering pure drinking water.
If you require any further advice on the desired flow rates or different types of water filters don’t hesitate to contact us at Aeon Water Filters – we will be only to happy to help out. Telephone (03) 9585 8866.