Most sumps include a filter sock mount, in 4 or 7 inch ring diameter. As water drains from the display into the sump, the sump sock traps waste to keep the sump clean. Wondering how to clean filter socks? They can be machine washed with basic bleach, no detergent. Run the washer a second time to rinse, or leave them out 24 hours so the chlorine can evaporate.