Media
To ensure a clean and healthy pond, there are three types of filter media that should be used: biological, chemical and mechanical. Biological media will help break down and remove sludge, waste and remove ammonia and nitrites. Chemical filter media will remove unsightly discoloration and harmful organic substances, while eliminating foul odors. Mechanical filter media will trap debris and particles that are in pond water. Pond filter media should be replaced monthly to ensure your water garden remains healthy.