Influence of Flow Rate and Dietary Protein Content and Source on the Operation of Biological Filters Used for Ornamental Fish, Barbus tetrazona, Production

Abstract An eight-week study evaluated the effects of flow rate and dietary protein on the function of sand and gravel biological filters for ornamental fish production. Forty tiger barbs, Barbus tetrazona, were placed in each of twelve, 38-L tanks. Upflow sand and gravel filters operated at non-fluidization flow rates of 57.5 L/hour and 111 L/ hour were compared. Diets with 32%, 40%, and 42% protein contents were compared. Total Ammonia Nitrogen (TAN) levels were significantly lower in the tanks with 57.5 L/hour filters. TAN levels were also significantly (P 0.05) by either flow rate or dietary protein level. Fish growth rate was not affected (P >0.05) by water flow rate, but gro...