These filter bags are designed to provide mechanical straining of fish system waste water or as chemical media bags for buffers or activated carbon. Normally a 200 micron bags will be used to remove the majority of solids before the water enters a biological filter. The 50 micron bag can be used in a filter setup using a a local loop to polish pre-treated water before being pumped back to a UV unit or direct to the fish holding tanks. Collar diameter is 180mm and bag length is approx. 290mm.