Tetra added something they call their Stay Clean technology to its Tetra Filter Cartridges and Bio-Bag Cartridges to help reduce buildup on your glass, bind smaller dirt particles for easier filtration and to stabilize pH.
The slow release tab is integrated into the filter cartridge and will slowly dissolve to help keep things looking better for longer. While this is no replacement to a regular maintenance program, it looks to help eliminate some of the negative side effects commonly experienced.
The Stay Clean tab is part of the medium and large filter cartridges and bio-bag systems in both a ready-to-use version and one that requires you to put it together. The assembly starts with putting the tab in a case in the middle of the filter assembly, putting the floss sleeve on and filling with carbon.