Quote:
Originally Posted by bertoni
I'm not sure why amino acids would work better for nitrate reduction, since they are a nitrogen source. I agree that the amount of carbon per unit of nitrate is significant, though. Maybe some organism is limited in growth by a missing amino acid. I'd stick with vinegar, ethanol, or bio-pellets for nitrate reduction, at least for a first attempt, but amino acid dosing can be helpful, at least in theory, depending on what's in the food going into the tank. It's interesting that you get good results. Maybe we should encourage others to give it a shot if they're stuck. More puzzles.
|
Yeah that is the question. I actually accidentally realized this. I was trying to raise nitrates by dosing amino acids, but more I dosed more it reduced ( I actually dropped to undetectable NO3 levels on salifert kit). Than I decided something was not right, I stopped dosing aminos and nitrate slowly started to increase. After that I started to use a mixture KNO3 and NaNO3 to increase nitrate. After that I realized dosing aminos increase nitrate consumption. Actually to a point that if you dose them together, nearly half of dosed nitrate disappears the next day.
While thinking about it I realized that at cellular level, it is quite common for cells to convert glucogenic amino acids to glucose and ketogenic amino acids to fatty acids. Actually this is how the metabolisms of carnivores work, their diets are very poor in carbohydrates (and fats depending on source) they basically convert amino acids to sugars and fats.
Now we dont know the exact amino acids composition of the amino acid additives. But if they have a large content of large amino acids like tyrosine, tryptophan, etc , it would mean they contain a lot more carbon than nitrogen. Plus these large amino acids are not very abundant in proteins, generally smaller amino acids are a lot more common. Below is a link showing the average amino acid content of E.coli proteins;
http://kirschner.med.harvard.edu/fil...upernatant.pdf
4 most common amino acids found in E.coli proteins is glutamate(5C,1N), asparatate(4C,1N), alanine (3C,1N) and glycine (2C,1N) . Aside from this I know glycine is commonly produced by cells as a osmoregulator, so it might be a lot more common outside of proteins. And 4 least common amino acids are tryptophan (11C, 2N) histidine (6C 3N), methionine (5C, 1N) and tyrosine (9C, 1N).
So if the amino acid supplement contained a lot of large amino acids, it would force cells break down the large amino acids and to absorb more nitrogen from the environment, in order to produce more of the smaller, more common amino acids. Like from a 11C tryptophan has enough carbon to built 5.5 glycine. But it only contain 2N, so to built 5.5 glycines a cell would need to pick up 3.5 molecules of nitrate. So it would cause nitrate uptake.
Does it provide any benefit over regular vinegar dosing, I doubt this. The only possible benefit might be uptake of some of the amino acids by corals and other inverts (especially clams). Plus it is hard to overdose it and excess can be removed by the skimmer. But it is far more expensive and can get contaminated.