We've been in our 8 year old home in Western NC for 5 months. We are on a well water system which consists of a deep well and a 3/4hp submersible pump. The treatment system has a 10X54 tank with air injection, 10X54 up flow AN tank with in & out head, Green sand filter for Iron and a water softener. I opened the sediment filter to find there was no cartridge in it so installed one. A week later the cartridge was full of dark silt and black gravel about the size of aquarium gravel. I'm thinking media from the up flow AN is escaping. After doing some research I'm convinced it would be best to convert it to a down flow Acid Neutralizer set up. I'm looking for advise on how to properly do this. Thanks, Paul C