Filter Canisters and Cartridges

This week we'll discuss filter canisters and their cartridges as used for treatment of residential water.

Water filter cartridges are a straight-forward way to remove unwanted substances from your water. Different cartridges are available that will remove sediment (sand, grit and other particles), chlorine, lead and other dissolved solids. These cartridges fit into a filter housing which has a removable cylinder for changing cartridges as they become saturated.

While this method of water treatment is considered "high-maintanence", it is a very effective way to filter water. These filter housings can be attached to your water lines either at the point of entry or just before your drinking water faucet, such as beneath the kitchen sink or before a refridgerator/freezer ice-maker/water dispenser. You will need to keep track of when your filter was last changed and keep a supply of inexpensive filter cartridges handy. It is considered wise to buy these filters a case at a time.

Most filter canisters have a pressure relief valve or button on them to ease the pressure on the cansiter making detachment of the canister much easier. Simply shut off the water supply before the filter housing and press the button. A cylinder wrench or oil filter wrench comes in handy for this procedure. The filter canisters use an o-ring for a leak proof seal, so make sure it's not damaged during the change-out process.

Various filters are available for various water treatment requirements. Activated carbon filters remove many elements such as chlorine, lead, sodium, taste and odor (sulfieds) and iron. Carbon block filters remove most of these elements but also add "freshness" to your drinking water.

There are iron and oil reducing cartridges, and even ion exchange cartridges for softening water. The cost of these cartridges makes then impractical for home or office use. They are intended for low-use applications such as RVs or camping. The larger carbon block filters (20-inch) are often used on whole-house water systems but much be changed regularly.

Water Value Company recommends using auto-backwashing filters for larger applications whenever possible.