A well water sediment filter is normally a particle filter. They are available in standard sediment filter cartridge diameter 10” & 20” long. Our big blue sediment filters have a larger diameter. Both types of sediment cartridge filters are available in 1,5,10 & 20micron ratings. String wound sediment cartridges look like a tight woven ball of string. They fit into a cartridge housing and act as a physical barrier to stop the sediment going into the rest of the water system.