Definitions for "Biological filter"
A bed of relatively inert material to promote or assist natural aerobic degradation of sewage.
A bed of sand, gravel, broken stone, or other medium through which wastewater flows or trickles, which depends on biological action for effectiveness.
a packaged treatment system that removes BOD and suspended solids from relatively small flows of sewage or industrial wastewater by passing the effluent over plastic media on which aerobic biofilm develops
a filter or a living environment where beneficial bacteria live
a media that cultivates beneficial bacteria
a must in pond keeping, and can be purchased or built to incorporate both mechanical and biological media
Keywords:  koi, keeping
a must in keeping Koi
a vessel where nitrification occurs and soluble waste is removed