Twin whole house, tank, rain and dam water filter systems are effective at filtering your entire water supply coming into the house. Can be used on town supply. They can also be used on Rain Water Tanks and gravity fed systems. Twin Whole House Tank water filter systems effectively reduce sedimnet, metals, chlorine taste & odor. Modifying the carbon water filter to a fine micron can also effectively reduce giardia, cysts and cryptosporidium. Each whole house water filter system comes complete and ready to install.