The lower the micron rating, the more floating debris it removes hence the filter socks clog up faster. Many hobbyists have both the 100 and 200 micron filter socks which allow them to swap out their 200-micron socks from time to time.

It depends on the tank load, but generally you want to change your filter socks once a week or every two weeks. The more often you change your filter socks, the better your water quality; it removes organic solids before they have a chance to further break down.

Ideally the filter sock should be hanging in the water without touching or laying on the bottom of the sump. If a shorter sock is above the water line there may be more noise as water drains from the sock side and splashes into the water In your sump.

Our socks are untreated. The felt is soft, flexible, and perfect for trapping floating debris from the water.

We have personally tested our filter socks in the reefer sliding shelf sock holder. Our filter sock material is thick and our plastic ring is slightly too large to drop through the hole in the shelf.

Owning an aquarium store and service company for 25 years meant that we had to test countless filter socks to find the best ones. One stood above the rest giving consistent and repeatable filtration performance in freshwater, saltwater, and reef tanks.