7 Filters for fluids, namely, for water and area-water solutions, in particular filtering systems that include biochar, namely a vessel or tube that allows a flow of a fluid through the vessel or tube and the vessel or tube includes biochar; Filters for fluids, namely, for water and area-water solutions, in particular filtering systems that include biochar and limestone aggregate, namely a vessel or tube that allows a flow of a fluid through the vessel or tube and the vessel or tube includes biochar and limestone aggregate; Filters for fluids, namely, for water and area-water solutions, in particular filtering systems that include biochar, limestone aggregate, and organic bacteria material, namely a vessel or tube that allows a flow of a fluid through the vessel or tube and the vessel or tube includes biochar, limestone aggregate, and organic bacteria material; Filters for fluids, namely, for water and area-water solutions, in particular filtering systems that include biochar, limestone aggregate, organic bacteria material and organic compost, namely a vessel or tube that allows a flow of a fluid through the vessel or tube and the vessel or tube includes biochar, limestone aggregate, organic bacteria material and organic compost