The WGB21BM whole house filtration system is a great "point of entry" filtration system for cleaning up well water. Unlike "point of use" systems (like reverse osmosis systems such as our RCC7 series) that are installed to supply water to a specific faucet, the WGB21B-PB filters your water from the source. This means water from every output in your home will have passed through the two filtration stages of the WGB21BM. The first stage of the WGB21BM houses a 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 up to 99% of chlorine from the water, and is highly effective on organic chemicals like herbicides and industrial chemicals. The second stage of the WGB21BM houses an iron and manganese reducing filter. The FM15B iron and manganese reducing filter is only included with the WGB21BM, as it is not needed for most municipal water supplies that the WGB21B targets. If you are on municipal (city) water or a generally clean water supply, you may want to consider the WGB21B over the WGB21BM. For removing contaminants and heavy metals like iron and manganese found in the majority of well water supplies however, the WGB21BM fits the bill. Note If lead is the major concern, you may instead want to look at using a filter specifically for lead such as the FCRC15B, which is included in our whole house systems WGB21B-PB.