Ammonia And Ammonium?

[Elrohirthehasty]

When we all talk cycling, we mention ammonia as that fist toxic thingy, but don't we mean ammonia AND ammonium?
 
Of course, these both depend on pH.  Low pH would mean you mostly have ammonium, while high pH would you mean you mostly have ammonia.  Maybe describing the interrelation is a bit confusing to newcomers (or those who could care less), but I think saying only ammonia is a tad misleading.
 
Opinions?

 

[coolie]

What's the actual point you are making mush?

 

[DrRob]

The problem with that is that the two exist in an equilibrium depending on the pH, so the two are largely inseparable in complex solutions.
 
I do agree though that in fish in cycles the concept is important to note as the toxicity of the ammonium is far less than that of the ammonia.

 

[eaglesaquarium]

0.25ppm total ammonia/ammonium (as measured by the API TEST KIT, for example) has so minor an amount of toxic ammonia, that it is actually not harmful in the least.
 

Source: http/www.aquaworldaquarium.com/Articles/TonyGriffitts/Ammonia.htm
 
In other words, total ammonia as measured on the test kit, is actually not really at a dangerous level for the fish until either the pH is above 8.0, or the concentration is greater than the test kit can actually measure.

 

[TwoTankAmin]

It is confusing. There is little need to understand the NH3 and NH4 relationship unless one is dealing with a fish in cycle. This is something the site does not recommend.
 
If one is doing a fishless cycle it is not relevant except for understanding why overdosing dechlor which contains an ammonia detoxifier is a bad thing to do. But all one needs to know is that it will slow a fishless cycle.
 
It is imperative to know about this subject if one is doing a fish in cycle as the goal there is not to change water until one must. Knowing this is much more complicated to understand. Then you must know how to calculate the NH3 level in your tank. But it doesn't end there. You also need to know how to calculate the amount of salt to add to counteract the nitrite. In fish in cycling, minimizing how many water changes one must do is important. Not harming fish is more important. Finding the balance for ammonia is tricky, nitrite can be handled without water changes in most cases with chloride.
 
For beginners, the less complicated things can be made, the better. Do a fishless cycle, follow the site's article on how to do it. Don't deviate, and almost all the time, it will be a snap and happen in about 5 weeks. If you get stuck in a fish in cycle from not knowing any better, add bacteria or get some fish out and then learn all the extra stuff needed if you insist on continuing with a fish in cycle.
 
But let me have some fun with perhaps misleading you some I am omitting the subscript and superscript charges + or -
 
Ammonia (NH3)
Ammonium (NH4)
Total Ammonia (TA)
 
But what is Total Ammonia Nitrogen (TAN) or
NH3-n
NH4-n
 
There are the two scales used in measuring ammonia, nitrite or nitrate. What is the difference in what they measure?
 
The thing is, how much of this is really important or necessary for most fish keepers to know?

 

[germanblueR]

The two scales either measure the free ion content of NH4/NH3, NO2, NO3 or they measure the nitrogen content of that ion. Ammonia-N and the other nitrogen readings are more typically used by water treatment plants and water quality analysis. The reported numbers are different for each test but they can easily be converted to the other scale by a simple multiplication factor. I know nitrate-N is 4.4 times lower then nitrate since thats the one mostly commonly encountered one IME. The rest I don't know off the top of my head but the multiplication value is the molecular weight of the ion divided by the amount of weight that is nitrogen, so its pretty easy to calculate.

I agree most people don't need to understand nitrogen content tests and the difference between them. However for those that look at their water quality reports would probably like to be saved a headache wondering why their API kit is reporting much higher numbers then their water utility. API is at least nice enough to give a very short explanation in the instructions for the nitrate test about the reported differences compared to nitrate-nitrogen tests.

Ammonia/ammonium and their pH relation/toxicity is something I think hobbyists should know since it can easily mean the life or death of stock. Also any products that deal with ammonia work by changing it to ammonium or an ammonium complex regardless of pH. However it will still show up on test kits since most read NH4/NH3 but report is as 'ammonia' which isn't exactly correct. Its also important to understand the product you are using if trying to detox ammonia. Seachem doesn't put it on their bottle but Prime will only bind ammonia, nitrite, and nitrate for 24-48 hours before it starts becoming inert and releasing the ions. Which again can mean life or death of stock in terms of ammonia and nitrite.

 

[TwoTankAmin]

Not bad.
 
The nitrogen scale is also used in a great deal of the lab research where it is relevant as well.
 
NH3 = NH3-N * 1.21589
NH4 = NH4-N * 1.28786
NO2 = NO2-N * 3.28443
NO3 = NO3-N * 4.42664
 
(Assumed atomic weights: H: 1.008, N: 14.007, O: 15.999)
 
For some reason one often sees these rounded and for some reason ammonia at 1.3 in used in many instances where it is not critical.
 
When you read what levels are bad for the bacteria its often in the nitrogen scale. The popular API kits (and many other hobby kits) read total ions. The level at which nitrite starts to impede the cycle and harm the bacteria is 5 ppm -N. So using the above conversion, on a total ion kit that would be about 16.4 ppm.

 

[Jan Cavalieri]

This is an old but very good thread which explains why I'm so concerned to always know how much ammonia vs how much ammonium there is in my tank as well as why I want to keep the PH down to around 7 - even then my total ammonia/ammonium is in 8 ppm level so even a PH of 7 would be too high - but if I go so acidic to neutralize the ammonia then I'd kill all the fish that can't handle low PH. I do have a kit that measures both ammonia and ammonium and it always shows 100% ammonium but that's because I add Prime and AmGuard almost daily and Prime with every water change - if I stopped doing that and stopped water changes then my fish would all die at 8.0 ppm ammonia since it would be back to 100% ammonia and 0% ammonium. Life is hell sometimes.