Bio Filter + Bio balls
UltraZap pressure Bio Filter for 5 litre media (media included)
Require 75 bio balls (black brick type)
For 2500 litre ponds with normal fish population
Flow rate 20-60 litre per minute. (1200-3600 litre/hour)
Biological filtration happens in the chamber containing living bacteria that populate the media in the filter. Fish excretes ammonia from their gills and toxifies the pond water they live in. Bio filtration is required to break down ammonia into nitrite and nitrite into nitrate to de-toxify the pond.