Biofiltration in ponds keeps gold fish and koi alive and healthy. Koi pond filtration is especially important.

The biofiltration cycle or biofiltration system in garden ponds is critically important to the ongoing health of pond fish. Biofiltration systems in ponds refer to purifying water first and foremost, not removing solids. Koi pond filtration cycle is described below

The picture below shows filtration in ponds taking place. The man is feeding fish - the food contains nitrogen. The food is converted by the fish to ammonia and this can be very poisonous if not removed in pond filtration systems. There is a cycle of events (called nitrogen cycle) taking place described on another web page designed to reduce the formation of dangerous chemical build up.

Look carefully at the picture and you will notice water in the koi pond filtration system is continuously circulating (24 hours per day is critical) through a box arrangement. This is a typical biofiltration system for small garden ponds.

The biofiltration system or filtration cycle depends upon correct sizing of the box and more importantly the contents of the biofilter container - called biomedia. You can build your own koi pond filtration system once you understand the principles well ... visit biological pond filters how to build your own