Most home  water filters  systems rely on activated carbon blocks, as this technology is extremely effective as well as cheap. However, you will have to replace carbon blocks every few months or so, depending on your water use. Improperly installed water filters will drastically reduce the life span of blocks, so proper installation of any system is a must. You may also consider installing a multistage system to give an added level of protection for you home and to prevent excessive sedimentation from reducing the lifespan of your activated carbon blocks.