I am curious as to what would cause ammonia or nitrite in a tank to increase? Will this only happen if a tank is not cycled? Or can it happen due to water changes, feeding, or overstocking?
What causes ammonia/nitrite increases?
- Thread starter DaisyTattoo
- Start date
Food+fish=ammonia+bacteria1=nitrite+bacteria2=nitrate.
Anything that changes one of these terms can upset the equation.
The bacteria live on things so waterchanges won't hurt them, but very aggressive gravel vaccing could bury a lot of them. They like oxygen so they tend to be on top of the substrate, not below the first little bit. This is the logic behind vaccing in patches.
A sudden increase in stocking or food could also cause a spike until the bacteria have had a chance to catch up. That'll usually happen pretty quickly in a healthy tank with an established cycle, but its the logic behind adding fish incrementally (unless you've done a fishless).
Spill a bunch of food in and you're likely to see a spike.
If you're getting random spikes that you can't trace to a root cause then that's bad. Send up the circumstances and I'm sure folks will get to work on it.
Anything that changes one of these terms can upset the equation.
The bacteria live on things so waterchanges won't hurt them, but very aggressive gravel vaccing could bury a lot of them. They like oxygen so they tend to be on top of the substrate, not below the first little bit. This is the logic behind vaccing in patches.
A sudden increase in stocking or food could also cause a spike until the bacteria have had a chance to catch up. That'll usually happen pretty quickly in a healthy tank with an established cycle, but its the logic behind adding fish incrementally (unless you've done a fishless).
Spill a bunch of food in and you're likely to see a spike.
If you're getting random spikes that you can't trace to a root cause then that's bad. Send up the circumstances and I'm sure folks will get to work on it.
Two things can cause ammonia/nitrite spike.
1. Reducing the population of beneficial bacteria so that the current population can no longer deal with the average ammonia production of it's residence.
This can be caused by removing a significant portion of filter media/gravel, improper cleaning of filter media, or overdosing a tank with antibiotic meds.
2. Increasing ammonia production so quickly that the current population of beneficial bacteria can't metabolize it quickly enough, and must increase thier population size in order deal with the new rate of ammonia production.
This can be caused by adding too many new fish at once, feeding more than you usually do, or failure to remove a dead tank resident before it starts to decompose.
Keep in mind that once a tank is firmly established, ammonia/nitrite spikes (sometime called mini-cycles, i hate that term) are rare, and pass so quickly that we usually don't even notice them. Bacteria reproduce by fission. Our species are relatively slow growing (in bacterial terms that means a generation time of about 24hrs ballpark). That means that theoretically you could double the bioload, and the bacteria population could grow to match it in a day or two. In actuality it takes a little longer, but you get the picture. Good question. Once you understand your bacteria, you understand alot of what happens in your tank.
1. Reducing the population of beneficial bacteria so that the current population can no longer deal with the average ammonia production of it's residence.
This can be caused by removing a significant portion of filter media/gravel, improper cleaning of filter media, or overdosing a tank with antibiotic meds.
2. Increasing ammonia production so quickly that the current population of beneficial bacteria can't metabolize it quickly enough, and must increase thier population size in order deal with the new rate of ammonia production.
This can be caused by adding too many new fish at once, feeding more than you usually do, or failure to remove a dead tank resident before it starts to decompose.
Keep in mind that once a tank is firmly established, ammonia/nitrite spikes (sometime called mini-cycles, i hate that term) are rare, and pass so quickly that we usually don't even notice them. Bacteria reproduce by fission. Our species are relatively slow growing (in bacterial terms that means a generation time of about 24hrs ballpark). That means that theoretically you could double the bioload, and the bacteria population could grow to match it in a day or two. In actuality it takes a little longer, but you get the picture. Good question. Once you understand your bacteria, you understand alot of what happens in your tank.
Ok, lets do a hypothetical.....lets say someone really overstocks their tank...lets just say someone put(god forbid) a couple of plecos, lets say a couple of goldfish, and ummm....a few tetras of some sort all into a 10g. Is there always going to be ammonia and or nitrite present, or will the bacteria eventually catch up even though the bioload is way too big for the tank? Sorry if the question seems redundant, I am just trying to understand how this actually works.
There are a few things I think you might see in a real over the top stocking situation.
The whole nitrogen breakdown process tends to acidify the water overtime. In a bad stocking situation you might see a pH crash. By the time you're into the low 6s there isn't a whole lot of bacterial activity. Lots of ammonium (the non-toxic form) building up. I think the little fellers die off just south of 5, but they start slowing down in the high 6s and have more or less stopped by the time the hit 6.0.
Both forms of bacteria (the ammonia-eaters and the nitrite eaters) need a good supply of oxygen: the chemistry they do relies on oxygen. Once the bacteria are in competition with the fish for O2 there is a limiting factor on the size of their population: they can't expand to enjoy the surplus food supply. You'd see spikes in that sort of enviroment.
The whole nitrogen breakdown process tends to acidify the water overtime. In a bad stocking situation you might see a pH crash. By the time you're into the low 6s there isn't a whole lot of bacterial activity. Lots of ammonium (the non-toxic form) building up. I think the little fellers die off just south of 5, but they start slowing down in the high 6s and have more or less stopped by the time the hit 6.0.
Both forms of bacteria (the ammonia-eaters and the nitrite eaters) need a good supply of oxygen: the chemistry they do relies on oxygen. Once the bacteria are in competition with the fish for O2 there is a limiting factor on the size of their population: they can't expand to enjoy the surplus food supply. You'd see spikes in that sort of enviroment.
Thanks Carpguy. I have been trying to figure all of this out. I had someone tell me that under no circumstances would ammonia or nitrite be above zero in a cycled tank. That confused me because when someone has a problem, ya'll always tell them to test the water. If there were no way for those things to be out of wack, why should they bother testing it? But now I have my answer, so thank you for taking the time to answer a newbies questions!