Nitrate in the Freshwater Fish tank
Introduction
Nitrates in water primarily result from the decay of autotrophs and from chemoheterotrophic life, for nitrates are a byproduct of the waste produced from the consumption of organic molecules as an energy source. Fish are the primary chemoheterotrophs in aquatic ecosystems; therefore, they are accountable for the majority of nitrogen found in water. Ammonia is the main component of fish waste, which is a very toxic compound of nitrogen, but aerobic ammonia oxidizers convert ammonia to nitrite via the intermediate hydroxylamine, which requires aid from ammonia monooxygenase and hydroxylamine dehydrogenase (1). Nitrite is an even more toxic form of nitrogen, but this is further oxidized to nitrate via another type of nitrogen bacteria with the enzyme nitrite oxidoreductase(1). In nature, nitrates are regulated to a certain extent through aquatic plant life, for it is essential in the production of chlorophyll (). In fish tanks, however, algae is the only natural nitrate regulator, but unlike more complex and nutrient dependent plants, algae is able to grow beyond the capacity of a given ecosystem with ease. Algae cannot convert nitrogen to a gas that can escape the system, so when it dies, nitrogen is released back into the system (). In closed systems, like that of a fish tank, mechanical work such as changing out volumes of water, being mindful in not overfeeding the fish, and cleaning off the algae and filtration systems, is required in order to ensure nitrate levels are kept at a safe and constant concentration. To investigate the outcome of partial water changes on the nitrate and nitrite levels in an freshwater aquarium containing convict cichlids, a consistent feeding plan was devised to ensure the differing nitrate levels in the water are not a result of a fluctuating diet or of decomposing food.
Materials and Methods
Fish Tank Set-Up The closed system for which data was collected consisted of a 39 gallon freshwater fish tank with convict cichlids. An Aquatop Canister Filter was connected to the fish tank via an auto-top-off... A feeding mechanism with the Zacro Automated Fish Feeder was devised so that 1.0 gram of TetraCichlid Floating Cichlid Pellets would be delivered twice a day. This was done by setting the automated fish feeder to release 1 meal portion at 8:30 and 16:30
Open System Comparison Freshwater samples from a creek and a pond were collected and analyzed on...from the locations displayed in figure 1.
References
1. Harms, G.; Layton, A. C.; Dionsi, H. M.; Gregory, I. R.; Garrett, V. M.; Hawkins, S. A.; Robinson, K. G.; Slayer, G. S. Real-Time PCR Quantification of Nitrifying Bacteria in a Municipal Wastewater Treatment Plant. Am. Chem. Soc. 2002, 37, 343-351.