Hi Byron
I was under the impression that the low mineral levels is affecting the bacteria growing for my cycle
This was only for my cycle & not for after its established. Am I right in thinking thats how it works?
I have never "cycled" an aquarium because I always have live plants, so I have never been concerned with cycling parameters. And my water is very soft, basically zero GH and KH and I do no buffering. So I don't want to mislead you, but the following excerpt from an article I wrote on another forum may explain some; endnote references in this excerpt are at the end.
Nitrification is the oxidation of ammonia/ammonium to nitrite and then the subsequent oxidation of nitrite to nitrate; this is performed by two groups of bacteria known collectively as nitrifying bacteria or nitrifiers. True nitrifying bacteria are autotrophs; they use chemosynthesis to manufacture their energy by using oxygen plus nitrogenous waste (ammonia or nitrite) and carbon (from CO2). There are several different bacterium species involved, all in the family Nitrobacteraceae, that carry out this function in soil, and it used to be thought that these, particularly
Nitrosomonas europa and
Nitrobacter, were the nitrification bacteria in freshwater. But Dr. Timothy Hovanec led the team of scientists that proved this to be a mistaken assumption. Ammonia is converted to nitrite by bacteria of the
Nitrosonomas marina-like strain [2] and nitrite is converted to nitrate by bacteria closely related to
Nitrospira moscoviensis and
Nitrospira marina. [3] With several subsequent scientific studies by other scientists on wastewater nitrifying bacteria this data is now accepted and confirmed scientific fact.
Once established, the population of these bacteria in an aquarium will be in direct proportion to the amount of ammonia or nitrite respectively. Nitrifying bacteria require 12-32 hours to multiply, which they do by binary division [each bacterium divides into two bacteria].
Nitrosomonas multiply in less time (12+ hours) while
Nitrospira require more time (up to 32 hours). In a new aquarium, it can take up to eight weeks for the bacteria populations to reach a level capable of eliminating ammonia and nitrite.
Scientific studies have also now proven that
Nitrospira are inhibited and cannot multiply in water that contains significant concentrations of ammonia, and evidence exists to suggest that existing populations of
Nitrospira actually become dormant when ammonia is present in high concentrations. Kim et al. (2006) determined that with an active ammonia [NH3] level of 0.7 mg/l (=ppm)
Nitrospira bacteria experienced a decrease of 50% effectiveness, resulting in an accumulation of nitrite. [4]
The pH has a direct effect on nitrifying bacteria. These bacteria operate at close to 100% effectiveness at a pH of 8.3, and this level of efficiency decreases as the pH lowers. At pH 7.0 efficiency is only 50%, at 6.5 only 30%, and at 6.0 only 10%. Below 6.0 the bacteria enter a state of dormancy and cease functioning. [5] Fortunately, in acidic water (pH below 7.0) ammonia automatically ionizes into ammonium which is basically harmless. And since nitrite will not be produced when the ammonia-oxidizing bacteria are in “hibernation,” this decrease in their effectiveness poses no immediate danger to the fish and other life forms.
Temperature also affects the rate of growth of nitrifying bacteria. It will be optimal at a temperature between 25 and 30C/77 and 86F. At a temperature of 18C/64F it will be 50%. Above 35C/95F the bacteria has extreme difficulty. At both 0C/32F (freezing) and 100C/212F (boiling) the bacteria die.
These bacteria cannot survive drying out; without water, they die. Tap water with chlorine may kill these bacteria, depending upon the level of chlorine and the duration of time the bacteria are exposed to it. Some antibacterial medications may negatively impact the nitrifying bacteria to varying degrees.
[2] Paul C. Burrell, Carol M. Phalen, and Timothy A. Hovanec, “Identification of Bacteria Responsible for Ammonia Oxidation in Freshwater Aquaria,”
Applied and Environmental Microbiology, December 2001, pp. 5791-5800.
[3] Hovanec, T. A., L. T. Taylor, A. Blakis and E. F. DeLong, “
Nitrospira- Like Bacteria Associated with Nitrite Oxidation in Freshwater Aquaria,”
Applied and Environmental Microbiology, Vol. 64, No. 1, pp. 258-264.
[4] Kim, D.J., D.I. Lee and J. Keller (2006), “Effect of temperature and free ammonia on nitrification and nitrite accumulation in landfill leachate and analysis of its nitrifying bacterial community by FISH,”
Bioresource Technology 97(3), pp. 459-468.
[5] Kmuda, “Aquarium Bacteria and Filtration Manifesto,” Parts 1 and 2, OscarFish website.