From a study of performance test of bio-filters in the Knicks system Aqua Pro. The objective is to test the performance of a bio-filter (Bio-filter) Aqua Pro systems Knicks great hotel that is actually ammonia mapen Chennai? The experiment was monitored and collected 12 times during the aqueous solution for various properties to analyze each have three points, are collected in a tank, fish tanks, before flowing out to the treatment plant and solution containers at a container planting from the circulation to the Bo to experiment with fish, which can be seen that only 23 percent of the ammonia from the fish tank that was changed to Chennai Hotel rotnai tank treatment.