Aimed at the current problems of capacious of hydrotreater, susceptible to plugging by microbe and the accumulation of ammonia or nitrite nitrogen in aquaculture, the aquarium (contain with the water treatment processor) using physical filtration + biodegradation + activated carbon adsorption complex process was devised to treat aquaculture for recycle. Under different working conditions, the effects of water temperature, hydraulic retention time (HRT), air flow and aeration mode on removal efficiency of ammonia, nitrite nitrogen and nitrate nitrogen (three nitrogen) in aquaculture. The test results showed that sludge yielding in the hydrotreater was low and hydrotreater was insusceptible to be plug. In addition, under the conditions of water temperature 25°C, air flow 1.5L/min,HRT 1.5h and intermittent aeration (aerating once every 1h), the removal rate of ammonia nitrogen , nitrate nitrogen and nitrite nitrogen was over 97.5% ,96% and 98.7% respectively, it means the three nitrogen was not detected. Therefore, the incorporated aquarium could permanently preserved favorable living environment for fish and could provide technological security for three nitrogen remove of fish farm water and for intensifying water recycle.