I am considering to install a whole house water filter of the backwash type. I am getting my water supply from the municipal and I think it would be good to have one to keep those pesky tiny impurities out. Our water filters are from UK, USA, Japan, Korea and China. Since I am going to be a first time user, my concerns are : 1. Maintenance cost 2. Life span of filtering media 3. Performance 4. FRP or Stainless Casing, which is better? 5. What am I getting into All input would be appreciated.