Nitrification Performance of Nitrobacteria Preparation for Marine Aquaria

Nitrification is an important process both in home aquaria and commercial aquaculture systems. In the biological ammonia removal system, the nitrifying activity of bacteria has been reported to be extremely low due to the slow growth rate of nitrifying bacteria, the inhibition of nitrification by free ammonia and nitrite ions. It is generally accepted that retaining a large amount of nitrifying bacteria within the biological nitrogen removal system is difficult to achieve, thereby making the nitrification the rate-determining step in the entire nitrogen removal process. To shorten the time needed for the establishment of the nitrification process, it's necessary to seed nitrifying bacteria inoculums to the aquatic environment. In this study, the effect of bacteria inoculums in marine aquarium water purification was determined. The results showed that the nitrifying bacteria exhibited obvious purification effect in marine aquarium. The application of nitrifying bacteria inoculums assures a total removal of TAN from 40 mg/l to below the detection limit within a period of 9 days. The nitrite reaches the peak concentration (37.4 mg/l) in day 9, and decrease to below the detection limit in day 15. In control group, however, the times that a total removal of TAN from 40 mg/l to below the detection limit is in day 25. The nitrite reaches the peak concentration (36.6 mg/l) in day 25, and decrease to below the detection limit in day 43. After input of nitrifying bacteria inoculums, ammonia- oxidizing bacteria and nitrite-oxidizing bacteria in marine aquaria increased rapidly in a short period of time and maintained TAN, nitrite at lower concentration levels. The time required to establish nitrification was shortened by about 60% of the time required without inoculation.