There are many types of filters on the market and they can treat a wide range of things and come in all sorts of shapes and sizes. But fear not! I will break down the most common types used and explain in more detail their applications so you can make the right choice.
TYPES OF FILTRATION
Sediment filters
Sediment filtered are usually made up of 3 common materials. Spun fibre, Pleated and poly woven. They all do the same job. The purpose is to remove the excessive solids in the water, either on its own or as a pre stage to protect the post filter in a system. Spun fibre and poly woven filters tend to capture a little more solids and are disposed of when used. A pleated sediment filter can be washed and reused if needed. However, most sediment filtered are relatively cheap so we advise that you dispose of these as well. Sediment filters range in physical size and in microns of filtration. The most common sizes are 10 x 2.5 inch for your standard under sink using 1 micron. 10/20 x 4.5 inch for whole house systems using 5 micron.
Sediment filters do not treat the water chemically and should be changed frequently between 6 to 12 months.
Activated carbon
Activated carbon filters ( ACF ) are the most commonly used filter for treating potable water. They are primarily made up of coconut shell. ACF are used to treat chlorine, chlorides, lead, taste, smell and bacteria if the aperture is low enough. ACF have come a long way over the years. These days they come infused with Metals such as silver and copper to aid in the protection of bacterial growth on the filter. ACF have a maximum absorption limit by the manufacturer. Therefor they should be disposed of and not reused every 6 to 12 months. ACF come in the same sizes and microns as the sediment filters.
A general rule for choice looks like this.
5, 10, 20 microns = Remove chlorines, solids and improve taste and smell
1 mic and below will remove lead, chlorine, solids, and bacteria.
Most carbon filters will not remove fluoride.
Ceramic
Ceramic filters (CF) are made from natural, organic materials, including fine silica powder, bone and coconut shell carbon. CF come in the usual sizes listed above. CF filters have a lot of misconception with them. Ceramics on their own will not treat water. The ceramic its self acts more like a sediment filter. This is why its important to check what the ceramics are combined with. For example. Carbon, aluminium, copper or KDF. These additional metals, minerals will do the heavy lifting in the water treatment. CF can be washed and reused that's why people choose them. However they tend to block very easy due to there fine pores and can be very slow in the production of water. Personally a filter is designed to used and disposed of in my opinion. That said it's still better than nothing.
Reverse osmosis membrane
Reverse Osmosis ( RO ) is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semi-permeable membrane. RO membranes are some of the best filtration methods available. The micron size is usually around 0.001 mic. The water is forced through and dived into Permeate and brine. Good and Bad water. The permeate is used and the brine is usually disposed of. Ro can remove almost everything from water essentially turning it into distilled water. therefore lacking in most good minerals required for the human body.
Reverse Osmosis Systems will remove common chemical contaminants (metal ions, aqueous salts), including sodium, chloride, copper, chromium, and lead; may reduce arsenic, fluoride, radium, sulphate, calcium, magnesium, potassium, nitrate, phosphorous and bacteria.
To combat the lack of minerals in the water are production they are usually added back in using a specific inline additive or just pink salt.
Due to the slow production rate of these systems a storage tank for the permeate water must be used.
These systems do require more maintenance and be a little costly. Systems range in size and cost depending usually on how much water is required for use daily. Because RO separates water there is a waist water component ranging from 10 to 50 % depending on incoming water quality.
Provided maintenance is done regularly on the pre filtration an RO membrane could potentially last up to years domestically.
Mixed Media
Mixed media ( MM ) refers to a loose mineral, metal, stone that is refined and used to polish, exchange, add or subtract properties of the waters structure. These consist of but are not limited to:
KDF = (Kinetic Degradation Fluxion) is high-purity copper-zinc granules that reduce contaminants in water using an oxidation/reduction (redox) reaction. It is used to treat heavy metals such as iron and can treat scale build up, bacteria, and prolong the life of post filters. Whilst it works very well it can be rather expensive and sometimes requires a system that can regenerate the KDF by back flushing using a a water softer.
Polyphosphate = Is a mineral used to combat hard water. It leaches slowly into water passing through to prevent further scale build. It does not remove calcium or lime from water but rather helps to reduce its effects. Phosphate is generally cheap and is a good addition to a pre filter to aid in protecting house hold appliances.
Thanks for taking the time to read. We hope you have gained some in site to making a better choice with your filters. Please read our other news articles on our website for more information regarding applications and other systems that can treat water.