Fishiesconfuseme
New Member
This could be a really stupid question but I was just wondering. Why do fish tanks suffer from ammonia spikes when overstocked, why can’t more bacteria grow to handle the ammonia?
Why can fish tanks be overstocked?
- Thread starter Fishiesconfuseme
- Start date
To start you off, I will copy over a section from an article I wrote on bacteria. Feel free to ask questions.
Nitrifying Bacteria
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.
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.
Nitrifying Bacteria
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.
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.
seangee
Fish Connoisseur
Please note that ammonia is not the only reason to avoid overstocking. Fish need adequate space (for swimming as well as personal space) and also release pheromones into the water. If they are too crowded they may become stressed which could lead to poor health or aggression. Also nitrate is the end product of the filtration process. In the long term this is harmful to fish and can only be reduced by water changes.
The reason for this post is just to say that the claims made on some sites, by some filter manufacturers, and popular on facebook groups that you can just buy a bigger filter and keep adding fish is both untrue and harmful to fish health.
The reason for this post is just to say that the claims made on some sites, by some filter manufacturers, and popular on facebook groups that you can just buy a bigger filter and keep adding fish is both untrue and harmful to fish health.
JuiceBox52 7
Artist, rare disease advocate, fish nerd, author
Tank of the Month 🏆
Pet of the Month 🎖️
Fish of the Month 🌟
Supporting Member ⭐
I agree, for instance even if you had a 100 gallon filter on a 10 gallon tank you still wouldnt want to put 50 guppies in a 10 gallon tank. Even if the filtration is ok they need space
too many fish may well increase nitrates to harmful levels...the higher your stocking the more often you need to do larger water changes...would you want to live in a small bathroom with 10 people?...your fish don't want to live in crowded polluted fish tanks either..
Lajos_Detari
Fish Herder
- Joined
- Aug 27, 2017
- Messages
- 1,746
- Reaction score
- 1,423
- Points
- 113
Another possible reason is "how long does it requires for the bacteria to process the ammonia and nitrite to nitrate"?
In a crowded tank, more ammonia will be produced before the bacteria can convert it to nitrite.
In a crowded tank, more ammonia will be produced before the bacteria can convert it to nitrite.
It’s like when you stuck in a toilet or crowded space, Ammonia, Nitrite and Nitrate is not the only problem.
Fish will stress when live in a small area
It’s like when you stuck in a toilet or in an elevator space.
Fish will stress when live in a small area
It’s like when you stuck in a toilet or in an elevator space.
Metalhead88
Fish Herder
- Joined
- May 31, 2019
- Messages
- 1,037
- Reaction score
- 697
- Points
- 113
I've seen first hand with family members that have overstocked tanks. Even in this case, there was no ammonia.... But nitrates were through the roof.
cupofjoel
Fish Crazy
- Joined
- Jun 17, 2019
- Messages
- 299
- Reaction score
- 115
- Points
- 43
This is a safe place so think any question is stupid.
I agree with all the members above and the analogies they used. I think overall, people who overstock their tanks tend to not care much about the fish, but more about having a lot of fish to feed and look at. None of us would want to live in a house with 100 other people...even if we can all "survive" in it.
Similar threads
Most reactions
-
769
-
409 -
306 -
242 -
212 -
193 -
183 -
177 -
176 -
160 -
155 -
140 -
100 -
88 -
75