Our reusable filter sock bags provide a final, impenetrable barrier when it comes to clean and pure rain water supplies, and are designed to keep out anything that might get through the mesh basket filtering system as it sits inside your rainwater tank. Sitting underneath the stainless steel mesh basket at the top of your rainwater tank means that all water gets maximum filtration before entering your rainwater tank. Water runs through the stainless steel basket and then runs through the filter sock bag as a second filtration. Most importantly, Our Filter Sock bags are 100% reusable and easily cleaned. We recommend for best results from your filter sock bag, putting it in the washing machine 2 – 3 times per year will keep it clean and working in perfect order.