Intro to water filters

Ordinary tap water is extremely safe to drink but sometimes, contaminants can come in contact with water and pass through our pipes and out of the faucets. Water filters serve to block these substances that can make our water taste bad. They also help calm nerves when it comes to safety reasons for filtering water.

Water filters are devices that are used to remove impurities through chemical or biological treatments or by allowing water to pass through several levels of fine obstructions to remove chemicals and particulate. They remove dirt, sand, bacteria, chlorine, and other unappetizing elements.

Some of the most common methods of purifying water are distillation and reverse osmosis. Bottled water is commonly produced using these two processes but for home use, they may not be too practical. They are expensive and rather slow, so the use of devices with cartridge filters are preferred in these situations.

Cartridge filters either utilize active carbon or ion exchange. Which one you choose should depend on what kind of water is coming out of your tap.

Active carbon filters
Activated carbon (charcoal) filters are a good choice if the tap water has a bad smell or taste. It can come in either granular (GAC) or solid block form. Carbon attracts bad elements as water passes through it. This type of filter is also effective in removing chlorine, pesticides and THM (trihalomethanes) to a certain extent. It also helps produce clear water by removing colorants that may be present.

Some popular brands that use activated carbon are Brita, Whirlpool and Aquapure. Their filters are either in GAC or carbon block forms and come in units that can be utilized for faucets, pitchers or refrigerator water filtration.

Activated carbon filters cannot remove fluoride or metals like copper and lead. Some carbon filters have activated nano-silver, which acts as an antibacterial so water is free from certain types of organisms. Carbon filters also cannot do anything to acidic water because it cannot change the water’s pH balance. Minerals that cause acidity are so tiny that they are not absorbed and can pass through these filters.

Activated carbon filters are easy on the budget because they are relatively inexpensive but to be effective, they need to be replaced regularly, probably every 3 to 6 months depending on usage.

Ion exchange filters
Ion exchange filters contain resins (tiny polystyrene beads) that purify water by attracting positively-charged chemicals like metals. These are called cation exchange filters. Filters which work by attracting negatively-charged chemicals like nitrate and fluoride are called anion exchange filters. Some ion exchange filters are equipped with both.

Two of the most common ion exchange processes are water deionization and softening. Deionization involves exchanging cations with hydrogen ions and anions with hydroxyl ions. Hydrogen ions combine with the hydroxyl ion to produce pure water.

Water softeners are an example of a cation exchange device. It removes calcium, iron and magnesium but adds sodium to the water. Ion exchange filters cannot remove some materials like chlorine and pesticides. Like active carbon filters, the filters become saturated with contaminants and require regular replacement units.

Other filters
Sediment filters prevent dirt and sediment from passing through and are often designed into a dual-cartridge filter system. These filters keep the main filter clean. Ceramic filters are effective in removing particles and chlorine.

Remember that cartridge filters should be replaced regularly. They usually come with a warning label that tells you how long it can be used. To make sure you remember to replace the filter, mark the date on your calendar when you installed the filter and the date when it should be replaced.

We can never tell the purity and safety of water just by looking at it or smelling it. Regular testing is performed at all local water sources to ensure safety and reports are made publicly available. Filtering water provides that extra layer of safety and removes the bad tasting elements from the water coming from our taps.

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