These filter bags made by TMC are great for polishing off water that contain fine debris and even micro bubbles. A stand can be purchased separately for easy instillation or you can simply put them in your sump. Available in 3 different micron sizes and are made from nylon or polyester to ensure maximum clarity.
All sizes are 4" in diameter and because of the shape they have a massive surface area so they work much better than a foam or wool.
Short Socks: 4" wide & 9" long
Long Socks: 4" wide & 14" long