PP Spun filters are made from high quality tightly spun fibre and are designed to filter out particle debris, such as dust, dirt, sand, rust.
Sediment filters are measured in micron sizes - the larger the micron number, the large size particle it will let through. The smaller the number, the cleaner the water.
All sizes are available in 20, 5 and 1 micron
20 Micron is coarsest - usually first in multiple housing set up, for larger particles
5 Micron - usually first or second in multiple housing set up
1 Micron - always last in multiple housing set up. For very fine dust, also can be used for filtration of cysts and parasites such as giardia.
Sediment filters should always go before a Carbon Filter so that they do the heavy lifting, and take out all the sediment, allowing the Carbon Filter which is last in the line, to work on dissolved matter. Carbon filters are not designed to filter sediment and particles.