What is a water filter and how does it work?

For homes and businesses, water filters are a convenient and clean device that removes harmful substances such as bacteria, viruses, heavy metals and chemical pollutants from water and making it safer for consumption.

How Do Water Filters Work?

Water filters operate through several mechanisms, depending on the type of filter used. The core processes involved in water filtration include physical filtration, chemical filtration, and biological filtration.

Physical Filtration: This method involves removing larger particles and sediments from the water through a physical barrier. Mesh screens, cloth filters, and ceramic filters are common physical filtration media that trap particles such as dirt, sand, and rust.

Chemical Filtration: Chemical filtration uses active materials like activated carbon to absorb and remove contaminants. Activated carbon filters are highly effective in removing chlorine, volatile organic compounds (VOCs), and other chemical impurities. The carbon's porous structure allows it to capture contaminants as water passes through.

Biological Filtration: Biological filtration involves the use of beneficial bacteria to break down organic matter and remove harmful microorganisms. This method is less common in standard home water filters but is used in more advanced filtration systems and in aquariums.

The Role of Water Filter Cartridges

Water Filter Cartridge: A water filter cartridge is a replaceable component that fits inside a water filter system. It contains the filtration media responsible for removing contaminants from the water. The type of cartridge used can vary based on the filtration needs and the specific contaminants present in the water supply.

Types of Water Filter Cartridges

1. Pre-Filter (PP Cotton Filter)

Function: The pre-filter, often made from polypropylene (PP) cotton, is the first line of defense against larger particles such as sediment, rust, and dirt. It helps protect subsequent filters from clogging by removing these larger impurities.

Replacement Period: Typically every 3 to 6 months.

Factors Affecting Replacement: The exact replacement period can vary depending on the quality of your water supply and how frequently you use your purifier. If your water has a high level of sediment or if you use your purifier extensively, you may need to replace this filter more frequently.

2. Activated Carbon Filter

Function: Activated carbon filters are essential for removing chlorine, bad odors, organic compounds, and other chemicals from water. They improve the taste and smell of drinking water.

Replacement Period: Approximately every 6 to 12 months.

Factors Affecting Replacement: If you notice a decline in water taste or smell before this period, it may indicate that the activated carbon filter needs changing sooner. Poor water quality or high usage rates can also necessitate more frequent replacements.

3. Ultrafiltration (UF) Membrane

Function: Ultrafiltration membranes are effective at removing bacteria and viruses while allowing beneficial minerals to pass through. They provide an additional layer of protection by filtering out microscopic contaminants.

Replacement Period: Generally every 2 to 3 years.

Factors Affecting Replacement: This timeframe can vary based on local water conditions and usage patterns. Regular maintenance checks can help determine if an earlier replacement is necessary.

4. Reverse Osmosis (RO) Membrane

Function: Reverse osmosis membranes are highly efficient at removing dissolved salts, heavy metals, and other impurities from water through a semi-permeable membrane process.

Replacement Period: Typically every 2 to 3 years.

Factors Affecting Replacement: RO membranes may need changing sooner if the input water quality is particularly poor or if the system is used heavily. 

5. Post-Carbon Filter

Function: The post-carbon filter acts as a final flit step before the purified water reaches your tap. It enhances taste by removing any remaining odors or tastes that might have passed through previous stages of filtration.

Replacement Period: Approximately every 1 to 2 years.

Factors Affecting Replacement: Replace this filter when there is a noticeable decline in water quality or taste.