Ammonia discussions

Ammonia can never be "zero" in a closed system,an aquarium,stocked with fish.The simple reason for this is because fish constantly produce ammonia through excrement and respiration,their gills.
Although you can't detect it with an aquarium grade ammonia test kit,doesn't mean it's not present in the aquarium.

 

Rudi, I accept that. Especially in the light that I have a very large bio load of 41 fish in the 4ft tank, that produce ammonia all the time. But the amount of ammonia is so minute, that it is virtually not there.

Let me try and explain how small this quantity is. I use the Milwaukee MI-407 low range ammonia calorimeter, accuracy ± 0.04 mg/L - 1.50 mg/L. It employs the Nessler method. That involves adding two reagents to 10ml of water. The reagents must stand 3.5 min and then you do the test, giving you the accuracy mentioned. Every time after that, that you measure the same sample, you get a higher reading, as the reagent react more and more with the sample. Now, I have repeated the test for up to hours later, meaning you should have a reaction by then, no matter how small the amount of ammonia is. But still, after this period, you still get a reading of zero. That tells me the ammonia is virtually zero and some bacteria is probably going to die off, causing a slight elevation in readings again. I do not know yet, but will know soon enough! I suspect I will get a jo jo effect as bacteria re-populate and die off again.

I am not a Chemist, so please tell me if I am missing something!

For all intense and purpose as an aquarist, the NH3 reading is zero, which I argued with Zoom is not possible, therefore my apology to him.

 

Tom,

When i meant you will have zero ammonia i was referring to zero reading, meaning that your tests will come up as zero, and your fish will be in an optimum environment with regards to ammonia. I do however have to agree Rudi that there HAS to be some sort of ammonia in the tank. The denitriying bacteria HAVE to have ammonia to survive. But what is happening is that because your filter is now established, the rate that the ammonia is being produced is directionally preportional to the rate its being removed. I would suspect that you would need a devicebeven more accurate to what you are using to register this ammonia though.

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We are all in agreement.

 

I see that. I think we all just explaining the same things in our own words.

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BTW Zoom, do you think it is going to jo jo?

 

I dont know. Id be very interested in the resuts.

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I.M.O. the ammonia in the tank will fluctuate,go up and down.Nobody feeds the same amount of food every time and the fish don't eat all the food always.Some are left over or falls between decor and there it will decompose if not cleaned out quickly.
The fish's metabolism also increases and decreases over a 24 hour period,they do go in a rest period at night and the ammonia production will slow down as well.
Water temperature also plays a role.If we take koi as an example,in winter feeding is reduced or halted completely because the fish's metabolism is so slow.Just before spring feeding is resumed but very slowly and very little food is given to help the fish adjust and for the filter bacteria to recolonise the filter media.
Overfeeding at this stage often leads to ammonia/nitrite poisoning and more often green water.

And then we have bacteria die off in the filter and substrate that happens constantly,and ammonia is produced through the decomposition.Plant leaves dying and leaking ammonia also adds to the load.This is one of the reasons I do a a 50% water change every week,to reduce and counter this potential build-up of biological components that occurs in heavily planted tanks and could cause ammonia spikes and algae issues.

 

Just for interest sake. I just measured a 29 hour old sample which gave a reading of zero when fresh. It now gives a reading of 0.23mg/l. Obviously wrong, but proving my reasoning earlier on that the reagent keeps on reacting with the water sample, the longer it stand. It also prove that although the reading was zero, there indeed was NH3 present.

Sorry Prof. I had to share this. ;-)

 

Is it not possible that something in that sample is dying off, andno bacteria is present to break it down?

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Interesting angle!

But I doubt that as the sample is taken from the top of the tanks clean water. I did new readings tonight and found the level is rising. The 3.5 min test still shows zero, but a reading just 40 min later gave a reading of 0.11mg/l.

 

I regularly refer to this thread, just to re-learn what I forgot. I am placing this diagram just as a means to quickly recap what the Nitrogen Cycle basically is.

 

Another reminder:
Ammonium (NH4+) is not toxic to fish. At above 7pH, some of this NH4 is turned into Ammonia (NH3), which is toxic. The higher above 7pH, the more NH4 is turned is turned into the toxic NH3.

 

Hi Tomk and others,

I am glad this thread has calmed down a bit here towards the end, but it has not calmed down enough, so I want to do some more calming.....

Firstly, Rudi pointed out that even if the filter was fully cycled, the ammonia levels would not be zero. In theory this is perfectly correct, in theory there will be a tiny amount of ammonia present all the time, but this is rock bottom low and not dangerous for fishes. You must actually realize that when a filter has matured, and if it has enough capacity, and by that I mean that there enough holes and nooks and crannies on the filter medium for the bacteria to sit in(ceramic rings, sponge, filter wool, you name it....) then there will be a large population of bacteria there that have established themselves and that are now just sitting there and are waiting for ammonia. They are sitting there drooling and saying "gimme ammonia man, I am hungry and want more, more man, more....". Why? Because they are actually getting energy out of breaking down the ammonia to nitrite. They use oxygen in the process, so starve them of oxygen and they may die, but if you have normal water circulation this will not happen and they will sit there "drooling for more ammonia". There are lots of these bacteria, hundreds of millions and each one wants ammonia and could not give a damn about the next bug next to him. So what I am saying is that a filter will always have too many of the bacteria in relation to the amount of ammonia produced by the fishes, and your capacity of ammonia breakdown is always higher than the amount the fishes will produce. These bacteria will definitely also sit on your normal gravel and plants. So, even if you add water with a tiny amount of ammonia in it, it will get gobbled up in no time. And if they do not get ammonia for a few hours they will also not die off, they may start dieing after 48 hours, but not within a 24 hour period.

Then on the second page of this thread, Jane very correctly wrote that she did not trust the test kit and this should already have told you that there was a problem with the kit and not with the amount of ammonia that you were measuring. YOU SHOULD IMMEDIATELY DOUBT any ammonia reading that you get from anywhere, because the bacteria that break down ammonia are so numerous and present everywhere that the chances that ammonia levels will be elevated anywhere should first be doubted before they can be believed. When you start of a raw aquarium, this is the only time when you can expect elevated ammonia levels really.

The Tom, and the English expression is "for all intents and purposes", you cannot perform any readings on any ammonia test kit if you let the reagents stand for even an hour as atmospheric oxygen will start reacting with the reagents. So just cancel any speculation on this, this is not valid!

Then Rudi mentioned that there may be periods of high ammonia production by fishes and then lower again. I would doubt that there would be any fluctuations over a 24 hour period, as the breakdown of amino acids in the fishes takes place at a constant rate and is released from the gills at a constant rate. So even if you do not feed the fishes, there will be ammonia production as there will be amino acids released from muscle breakdown of the fishes.

Bottom line is that there will not be spikes in ammonia production and there will also not be spikes of ammonia caused by a lack of capacity by the bacteria because they are not functional in a normal aquarium with an actively functioning filter over a 24 hour period.

However, if you have a power fail and then have a lack of oxygen in the filter, then you can have upsets, but those upsets will normally appear as nitrite spikes and not as ammonia spikes and the bacteria that breakdown ammonia are more active than those that break down nitrite.

BUT, and I would like to refer you guys to your aquarium bible reading for the day, read this part in "The Manual of Fish Health" and if you read it carefully, it is all there.

And that is my last sermon for the day, I now have some work to do this evening.

Kind regards,

Dirk

 

Dirk, as quoted above, this is the second time you are pointing out my mistake. I already acknowledged my mistake. Should I ask @Rory to go to the offending post and do a correction?

Thought I would just mention. The sample with reagent is in a sealed bottle with lid, in the meter. It is not in contact with atmospheric oxygen, nor light. It is also peculiar that when you take a control sample of water, in which you know there is no ammonia, this reaction over time does not happen.

 

Hi Tom,

Ag come now Tom, you can take a bit of leg pulling, we all like you very much and we appreciate that you are trying to learn, so moenie worry nie.... The other thing that I am pretty sure of is that most English people actually don't get that expression "for all intents and purposes" right, so don't be offended and the mods don't need to do any correcting.....

As soon as you add the reagents together in a reaction in which colour is formed as in many of these test kits, this colour will get more intensive with time, often regardless of whether oxygen is present or not. The bottom line is if the instruction say that you should read within a certain amount of time, then do the reading then and forget about anything after that. What I also want to say is that if your control samples does not contain any ammonia and this samples is then negative for colour, then this will not increase in colour because there is no ammonia for starters.

Kind regards,

Dirk

 

Dirk, the test I am talking about is not a drop test, that changes color. It is the MI407. (Martini)

 

I wouldn't even know where to start modding....

 

Actually @TomK, it IS a drop test

you added drops of reagent , didn't you?

It's just not immediately evident to consumer-hobbyists.
This Modified Nessler reaction for low range ammonia detection and measurement is all the chemistry there is really.
the same type reaction employed by ordinary hobby tests, albeit more methodical for lesser user-interference.

We call this Simple COLORIMETRY.
As you can see, it implies "measuring (by) Colour"

Instead of your eyes, and brain cross-referencing test solution against a colour chart after you've added drops in accordance with instructions, you NOW have circuitry , light cell, cuvette, light sensor, test reagents , solution, software and an LCD display...

it is the SAME COLOUR and procedure, however, now measurement is by electronic-photometric means.

The unit is merely an economically feasible, convenient Spectrophotometer, which measures light, and it's passage through the solution...and correlates that with known values in a relationship we know as the Beer-Lambert 's Law.
[There is a linear relationship between absorbance and concentration of substance under test, in solution]

nice piece of kit by the way. I have another brand, multiparameter Spectrophotometer, and had the Big Brother to your machine a few years back.

 

hehe, @Altum, you got me!

Now, what about the argument that the longer it stands, the more the reaction and higher the reading. If it says zero after about 24 hours, then it really is zero. If there is minute ammonia present, it will give some reading after some time.

That is my experience in any case.