The REAL Guide to Water Filter
Water filters remove things that are harmful to your health, things that can increase the chance of getting cancer, and things that taste or smell bad. The physics of filters is based on sieving, ion exchanges and other processes. Pur and Brita are two well known brands. Today, whole house water filters are available aswell as portable and refrigerator systems.
Water Filters
A filter is a device which removes impurities from water by means of a fine physical barrier and/or chemical processes. Filters are used to cleanse water for irrigation, drinking water, aquariums, and swimming pools. Water Filters can be bought at stores to filter drinking water. Two major brands are PUR and Brita. These water filters remove things that are harmful to your health, things that can increase the chance of getting cancer, and things that taste or smell bad. The phyiscs of filters is based on sieving, ion exchanges and other processes.
Drinking Water Purification
In July 2002, Singapore announced that a process named NEWater would be a significant part of its future water plans. It involves using reverse osmosis to treat domestic wastewater before discharging the NEWater back into the reservoirs.
In the United States, household drinking water filtration systems, including a reverse osmosis step, are commonly used for improving water for drinking and cooking. Such systems typically include four or five stages:
- a sediment filter to trap particles including rust and calcium carbonate
- optionally a second sediment filter with smaller pores
- a carbon filter to trap organic chemicals and chlorination
- a reverse osmosis filter with a thin film composite membrane (TFM or TFC)
- optionally a second carbon filter
Media Filter
A media filter is a type of filter utilizing a bed of sand, crushed granite or other material to filter water for drinking, swimming pools, aquaculture, irrigation, and other applications.
One design brings the water in the top of a container through a "header" which distributes the water evenly. The filter "media" start with fine sand on the top and then graduatingly coarser sand in a number of layers followed by gravel on the bottom, in gradually larger sizes. The top sand physically removes particles from the water, the job of the subsequent layers is to support the finer layer above.