Your water could contain chemical contaminants from pesticides, petroleum, solvents, or a variety of sources. Some water contains lead, mercury or other heavy metals. Filter Prep has a variety of units to remove these contaminants With a Filter Prep water filtration system, you can protect appliances, household plumbing, and your water heater by reducing sediment, sand or rust that can damage plumbing and appliances. Filter Prep automatic filters can eliminate iron, sulfur and odor from your water supply 24 hours a day, in most cases, without having filter cartridges to change or chemicals to purchase.