Filter sand includes anaerobic bacteria, facultative anaerobic bacteria, aerobic bacteria, and another 10 kinds of bacteria. Each bacteria is compounded from 10,000 to 10,000,000 pcs/g.
There are over ten kinds of Aerobic bacterium in Filter Sand which include heterotrophic bacteria and autotrophic bacteria.
Heterotrophic bacteria decomposes organic matter into inorganic matter. (ie. They decompose protein, carbohydrate and fat into inorganic matter.)
Autotrophic bacteria decomposes inorganic matter into smaller matter. (ie. They decompose ammonia into nitrous acid, nitrate, and nitrogen gas.)
As the bacteria act they generate energy, as well as making vitamins and antibiotics (effective into mould) as by-products. Some of the bacteria within Filter Sand also produce an enzyme which forms structures to promote bacterial growth. In addition this is used by other living things, helping the formation of an effective ecosystem.
Remember the big differences between the natural mud pond and the hobbiest pond. In the natural mud pond there are lower stocking levels and the natural filter system of mud and sand. In the hobbiest pond stocking levels are higher, causing the filters to have to work harder making the activity of the bacteria the most important area for keeping good water in the pond.
Because hobbiest ponds are also prone to sudden changing of water quality, which may harm the filter bacteria, it is very important to add Filter Sand once a month to maintain good water .