The WGB21B is a great “point of entry” filtration system and excellent alternative to the larger WGB22B (4.5″X20″) for smaller homes or where limited space may be a concern. Unlike “point of use” systems the WGB21B will filter water directly from your source. This means that water from every outlet in your home will have passed through this filter, providing up to 50,000 gallons of clean water for the entire family. The first stage of this system houses a 5-micron high-capacity polypropylene sediment filter (FP15B). This filter is responsible for removing dirt, rust, and most suspended solids, to protect and extend the life of the CTO carbon block filter. The second stage houses the 5-micron CTO coconut shell carbon block filter (FC15B). Block carbon is more effective than other forms of carbon in that it is finely ground up carbon packed into a solidified block. This means they have a higher density than other types of carbon filters, and are therefore more effective in removing their targeted contaminants. The carbon block filter knocks out bad tastes and odors, removes over 90% of sediment and chlorine from the water, and is highly effective on organic chemicals (VOCs) like pesticides, herbicides, and industrial chemicals. If you are on city water, your local water utility must meet very strict Federal and State standards for purity. Almost all municipally treated water is chlorinated, and this can affect taste and create odors in the water. The WGB21B filtration system will remove these tastes and odors. If you are on a private well or spring, you should have your water tested. You may also want to contact our technical staff in Alpharetta GA at (678) 261-7611 for help in selecting the best filter system for your water chemistry.