I have been using them since i sent the tank up in Feb. this yr. 100 micron bags and change every 2 days. Sometimes every morning as I have 20 bags which is enough for ten days. Every weekend I turn them inside out and them spray with a water hose inside a plastic tote that has holes in the bottom. Gets them pretty clean (in less than a hour) then toss them in the washing machine hot water with a splash of bleach. Rinse, then wash cycle with no bleach they look like new. It is amazing how dirty they are in just 2 days. 125 gals soft coral and a large mated pair of Clarki clown fish, cuban hogfish, sailfin tang, hippo tang, purple tang, foxface, Flagfin Angelfish, and the smallest of them all is a blue devil dansel that is 3 inchs long.