How long does fish need to adjust low salinity to normal salinity

[Lasse]

That would equate to a total NH3-N concentration of 8.5 mg/l

What are you talking about?

un-ionized ammonia is NH3 or the gas NH3.
Ionized ammonia is NH₄⁺ - the ion from the gas NH3.
NH3-N is the N part of the gas NH3 or the N part of the un-ionized ammonia
NH₄⁺-N is the N part of the NH₄⁺ or the N part of the ionized ammonia.

"0.57 ppm of un-ionized ammonia" at a pH of 8.1, that would equate to a TOTAL ammonia level of 8.5 ppm - and that's unheard of!

Maybe you have not heard about it but they discover issues with the gills (sub lethal damage) at this concentration. Its not a LC50 figure

If the unionized ammonia expressed as NH3-N is 0.57 - the unionized ammonia expressed as NH3 is 0,57*1,21 = 0,69 mg/L NH3. This experiment was done in 27 ppt saltwater, 27 degree C and a pH of 8.15. In this case - back calculation give a total ammonia (NH3+NH4 or ammoniac+ammonium) of around 7,6

was your ammonia chloride dose that high?

Its a strange question because in the methods the authors state - my bold

0.23 ± 0.02, 0.57 ± 0.03, 0.97 ± 0.06, 1.05 ± 0.06, 1.22 ± 0.05 and 1.63 ± 0.14 mg/L NH3-N obtained by adding ammonium chloride

Total ammonia nitrogen (TA-N) and nitrite were measured according to Grasshoff et al. (1999) and Aminot and Chaussepied (1983). Un-ionized ammonia (NH3) concentrations were calculated following TA-N, and temperature, salinity and pH values following the equations of Ostrensky et al. (1992), adapted from Whitfield (1974) and Bower and Bidwell (1978).

Apparently - they have add so much ammonium chloride it was needed to get 0.57 mg/L NH3-N. Note that 0.57 mg/L NH3-N is not with in the LC but they could show gill lesions

Once again
un-ionized ammonia is NH3 in British English even named ammoniac
Ionized ammonia is NH₄⁺ - in British English even named ammonium
Total ammonia is the sum of NH3 and NH₄⁺ or in British English ammoniac+ammonium

Is there a -N in the the formula - it means that the mg/l refers to only the N part of the subject. If you have NH3-N - you need to multiply with 17 (mol mass NH3) divided with 14 (mol mass N) = 1,21 if you want to express it as NH3

Most important is that their findings of LC50 is well in line with other similar investigations of salt water fish there the LC50 96h value can vary from around 0.5 up to 2-3 mg/L NH3-N for LC50 96 H (4 days)

Sincerely Lasse

 

[Jay Hemdal Verified Community Expert]

What are you talking about?

un-ionized ammonia is NH3 or the gas NH3.
Ionized ammonia is NH₄⁺ - the ion from the gas NH3.
NH3-N is the N part of the gas NH3 or the N part of the un-ionized ammonia
NH₄⁺-N is the N part of the NH₄⁺ or the N part of the ionized ammonia.




Maybe you have not heard about it but they discover issues with the gills (sub lethal damage) at this concentration. Its not a LC50 figure

If the unionized ammonia expressed as NH3-N is 0.57 - the unionized ammonia expressed as NH3 is 0,57*1,21 = 0,69 mg/L NH3. This experiment was done in 27 ppt saltwater, 27 degree C and a pH of 8.15. In this case - back calculation give a total ammonia (NH3+NH4 or ammoniac+ammonium) of around 7,6


Its a strange question because in the methods the authors state - my bold




Apparently - they have add so much ammonium chloride it was needed to get 0.57 mg/L NH3-N. Note that 0.57 mg/L NH3-N is not with in the LC but they could show gill lesions

Once again
un-ionized ammonia is NH3 in British English even named ammoniac
Ionized ammonia is NH₄⁺ - in British English even named ammonium
Total ammonia is the sum of NH3 and NH₄⁺ or in British English ammoniac+ammonium

Is there a -N in the the formula - it means that the mg/l refers to only the N part of the subject. If you have NH3-N - you need to multiply with 17 (mol mass NH3) divided with 14 (mol mass N) = 1,21

Most important is that their findings of LC50 is well in line with other similar investigations of salt water fish there the LC50 96h value can vary from around 0.5 up to 2-3 mg/L NH3-N for LC50 96 H (4

What are you talking about?

un-ionized ammonia is NH3 or the gas NH3.
Ionized ammonia is NH₄⁺ - the ion from the gas NH3.
NH3-N is the N part of the gas NH3 or the N part of the un-ionized ammonia
NH₄⁺-N is the N part of the NH₄⁺ or the N part of the ionized ammonia.




Maybe you have not heard about it but they discover issues with the gills (sub lethal damage) at this concentration. Its not a LC50 figure

If the unionized ammonia expressed as NH3-N is 0.57 - the unionized ammonia expressed as NH3 is 0,57*1,21 = 0,69 mg/L NH3. This experiment was done in 27 ppt saltwater, 27 degree C and a pH of 8.15. In this case - back calculation give a total ammonia (NH3+NH4 or ammoniac+ammonium) of around 7,6


Its a strange question because in the methods the authors state - my bold




Apparently - they have add so much ammonium chloride it was needed to get 0.57 mg/L NH3-N. Note that 0.57 mg/L NH3-N is not with in the LC but they could show gill lesions

Once again
un-ionized ammonia is NH3 in British English even named ammoniac
Ionized ammonia is NH₄⁺ - in British English even named ammonium
Total ammonia is the sum of NH3 and NH₄⁺ or in British English ammoniac+ammonium

Is there a -N in the the formula - it means that the mg/l refers to only the N part of the subject. If you have NH3-N - you need to multiply with 17 (mol mass NH3) divided with 14 (mol mass N) = 1,21 if you want to express it as NH3

Most important is that their findings of LC50 is well in line with other similar investigations of salt water fish there the LC50 96h value can vary from around 0.5 up to 2-3 mg/L NH3-N for LC50 96 H (4 days)

Sincerely Lasse

Lasse,

You wrote a lot there, but didn't address the issue that I have with this paper. Let's look at one simple conclusion from their abstract:

They state that the 24 hour LC50 for clownfish was 1.06 mg/l un-ionized ammonia. They state that their pH was 8.15

By my rough figuring, that gives a TAN of about 9 to 10 mg/l! I have a strong suspicion that although they wrote "un-ionized NH3" they truly meant TAN. If you substitute TAN for all of their numbers, it lines up quite well with what I empirically know to be true - a TAN of from 0.8 to 1.5 mg/l at marine pH levels is dangerous for fish - full stop, end of story.

My only mistake was using the term "total NH3-N" instead of TAN. They did not use the term TAN in their article, so I wanted to try and explain it by saying that. I also translated my letter into Portuguese in case English might have proven a barrier.

 

[Lasse]

a TAN of from 0.8 to 1.5 mg/l at marine pH levels is dangerous for fish - full stop, end of story.

My only mistake was using the term "total NH3-N" instead of TAN. They did not use the term TAN in their article, so I wanted to try and explain it by saying that. I also translated my letter into Portuguese in case English might have proven a barrier.

IMO - you have not understand the concept of LC50 96 H the right way.It doesn't say that numbers below this won't kill or hurt fish during 94 hours. - it only says that concentration of this type kill 50% of the tested population during a 94 H expose in their test run. That´s it. Its the scientific accepted test of acute toxicity. In this way this study is in line with many other studies of LC50 in marine fish.

The true deadly or harmful concentration for a species is always depended on individual circumstances.

IMO - you have rejected a scientific study just because you didn't understand the concept. They are NOT saying that lower concentrations don't kill fish or are harmful to fish - they are only saying that at these concentration of NH3-N, 50% of the test population died within 24, 36, 48 and 92 hours in their test run.

Your claim that TAN of 0.8 to 1.5 mg/L its dangerous for fish without mention salinity, temp and pH can be both true and false - it all depends on salinity, temp and mostly by pH. And thank´s god for that - if it was not like that it should be impossible to transport fish in plastic bags for a prolonged time - I have measured pH of lower than 6.7 and TA higher than 5 mg/L in bags transported for 48 H - and no problem with fish - this because the deadly NH3 concentrations during this low pH only is around 0.012 mg/L NH3-N.

However - I agree with you that during normal temp, salinity and pH in a reef aquarium 0.8 mg/L TAN (Total Ammonia Nitrogen) corresponding to around 1 mg/L TA in a normal reef (Total Ammonia) can be deadly for individuals of many reef fish species and probably cause sublethal damage in lower concentrations.

But this was not what we discuss here - your claim was that these people was flawless with their scientific reports and use this report in order to doubt the one I link to.

IMO - this report fulfil the scientific standards and I do not see a reason to doubt either this study or the one I linked to.

Sincerely Lasse

 

[Jay Hemdal Verified Community Expert]

IMO - you have not understand the concept of LC50 96 H the right way.It doesn't say that numbers below this won't kill or hurt fish during 94 hours. - it only says that concentration of this type kill 50% of the tested population during a 94 H expose in their test run. That´s it. Its the scientific accepted test of acute toxicity. In this way this study is in line with many other studies of LC50 in marine fish.

The true deadly or harmful concentration for a species is always depended on individual circumstances.

IMO - you have rejected a scientific study just because you didn't understand the concept. They are NOT saying that lower concentrations don't kill fish or are harmful to fish - they are only saying that at these concentration of NH3-N, 50% of the test population died within 24, 36, 48 and 92 hours in their test run.

Your claim that TAN of 0.8 to 1.5 mg/L its dangerous for fish without mention salinity, temp and pH can be both true and false - it all depends on salinity, temp and mostly by pH. And thank´s god for that - if it was not like that it should be impossible to transport fish in plastic bags for a prolonged time - I have measured pH of lower than 6.7 and TA higher than 5 mg/L in bags transported for 48 H - and no problem with fish - this because the deadly NH3 concentrations during this low pH only is around 0.012 mg/L NH3-N.

However - I agree with you that during normal temp, salinity and pH in a reef aquarium 0.8 mg/L TAN (Total Ammonia Nitrogen) corresponding to around 1 mg/L TA in a normal reef (Total Ammonia) can be deadly for individuals of many reef fish species and probably cause sublethal damage in lower concentrations.

But this was not what we discuss here - your claim was that these people was flawless with their scientific reports and use this report in order to doubt the one I link to.

IMO - this report fulfil the scientific standards and I do not see a reason to doubt either this study or the one I linked to.

Sincerely Lasse

Lasse,

Again, you are avoiding the FLAW in this study. They either mistakenly called TAN as “un-ionized” ammonia, or they DID calculate in-ionized ammonia correctly, but then their fish survived 8 to 10 TIMES the expected TAN! I firmly believe the former was the issue. That’s why I asked the author how much ammonium chloride they used to spike their study tanks. That would tell me right away what the issue was.

I do understand LC values, and I have a fair knowledge of the chemistry involved.

 

[Lasse]

DID calculate in-ionized ammonia correctly, but then their fish survived 8 to 10 TIMES the expected TAN! I firmly believe the former was the issue.

Again, you are avoiding the FLAW in this study

No I do not - the study show that 50 % of the population died and 50 % survived at a NH3-N levels they show in the test run. And they clearly did not did any confusion between TAN and NH3-N. You never thought that your assumption that around your believe that 100% of the fish will die above a TAN of 1.5 can be wrong - not based in scientific research?

I found an article that state

The average of the mean acute toxicity values for 32freshwater species is 2.79 mg NH3/l compared with 1.86mg NH3/l for 17 seawater species, taken from data reported in the USEPA (1984, 1989) reports, respectively

Sincerely Lasse

 

[Jay Hemdal Verified Community Expert]

No I do not - the study show that 50 % of the population died and 50 % survived at a NH3-N levels they show in the test run. And they clearly did not did any confusion between TAN and NH3-N. You never thought that your assumption that around your believe that 100% of the fish will die above a TAN of 1.5 can be wrong - not based in scientific research?

I found an article that state


Sincerely Lasse

Lasse,

Do we have a problem with a language barrier here?

The LC numbers are not any part of my issue with this paper!

The crux of the issue is if they misunderstand the difference between un-ionized ammonia and TAN. They never mention TAN in the paper at all, which leads me to wonder if they do not understand what it is.

As I said, if I knew how much ammonium chloride they used to spike their samples, I could resolve this issue.

Im camping at the moment, and can’t do the math well in my head, but let’s take their spiked sample that they report to have around 1 mg/l un-ionized NH3. To reach that level, at the temperature and pH of their water, they would have to add about 14 mg/l ammonium chloride. That would also have a TAN of about 10 mg/l. That is a crazy high level!

On the other hand, if they say un-ionized ammonia, but actually are measuring TAN, then that gives an un-ionized ammonia level of about 0.1 mg/l. And that lines up with typical toxicity levels in marine aquariums. I think that is what happened here…..

 

[Lasse]

They never mention TAN

I wonder if there is something wrong with my understanding of written English because int the meyhodology part they write my bold

Total ammonia nitrogen (TA-N) and nitrite were measured according to Grasshoff et al. (1999) and Aminot and Chaussepied (1983). Un-ionized ammonia (NH3) concentrations were calculated following TA-N, and temperature, salinity and pH values following the equations of Ostrensky et al. (1992), adapted from Whitfield (1974) and Bower and Bidwell (1978).

I understand that the measured TAN and calculate actual un-ionized ammonia (NH3) from that - maybe are not my English reading capability enough and I missunderstand this? But I do not think so - IMO - they had not missunderstand the difference. They know the difference between TA-N and NH3-N

I redo my back calculations (using this tool)

The LC50- 24, LC50-48, LC50-72 and LC50-96 h were estimated to be 1.06, 0.83, 0.75 and 0.75 mg/L for NH3-N. Salinity was 27 ppt, temperature 27 degree C and pH 8.15 - the corresponding TA-N from this will be 11.4, 9.1, 8.2 and 8.2 mg/L TA-N (Total Ammonia Nitrogen). This correspond to TA (Total Ammonia) of 14.67, 11,67, 10.5, 10.5 mg/L respectively in this salinity, temp and pH. As an example - if we take the 0.75 mg/L for NH3 and let the pH be 8.5 instead for 8,15 - the TA-N will be 4 mg/L. If the pH is 7.8 instead - the TA-N will be 17.5 mg/L. This is the reason why TA or TA-N is not good parameters in order to investigate ammonia toxicity. NH3 or NH3-N concentrations as LC50 are independent of pH because its calculated with help of TA (TA-N), pH, temp and salinity, You may see it crazy high - but this is the result.

My English is maybe not good because you seems not understand that these results from these authors is in line with other LC-50 studies according to NH3 (or NH3-N) concentrations for marine species even if I have stressed this many times in this thread. In my latest post I had the quote

The average of the mean acute toxicity values for 32freshwater species is 2.79 mg NH3/l compared with 1.86mg NH3/l for 17 seawater species, taken from data reported in the USEPA (1984, 1989) reports, respectively

You have not comment this - 1.86 mg/L NH3 correspond to 1.52 NH3-N

Sincerely Lasse

 

[Jay Hemdal Verified Community Expert]

I wonder if there is something wrong with my understanding of written English because int the meyhodology part they write my bold



I understand that the measured TAN and calculate actual un-ionized ammonia (NH3) from that - maybe are not my English reading capability enough and I missunderstand this? But I do not think so - IMO - they had not missunderstand the difference. They know the difference between TA-N and NH3-N

I redo my back calculations (using this tool)

The LC50- 24, LC50-48, LC50-72 and LC50-96 h were estimated to be 1.06, 0.83, 0.75 and 0.75 mg/L for NH3-N. Salinity was 27 ppt, temperature 27 degree C and pH 8.15 - the corresponding TA-N from this will be 11.4, 9.1, 8.2 and 8.2 mg/L TA-N (Total Ammonia Nitrogen). This correspond to TA (Total Ammonia) of 14.67, 11,67, 10.5, 10.5 mg/L respectively in this salinity, temp and pH. As an example - if we take the 0.75 mg/L for NH3 and let the pH be 8.5 instead for 8,15 - the TA-N will be 4 mg/L. If the pH is 7.8 instead - the TA-N will be 17.5 mg/L. This is the reason why TA or TA-N is not good parameters in order to investigate ammonia toxicity. NH3 or NH3-N concentrations as LC50 are independent of pH because its calculated with help of TA (TA-N), pH, temp and salinity, You may see it crazy high - but this is the result.

My English is maybe not good because you seems not understand that these results from these authors is in line with other LC-50 studies according to NH3 (or NH3-N) concentrations for marine species even if I have stressed this many times in this thread. In my latest post I had the quote



You have not comment this - 1.86 mg/L NH3 correspond to 1.52 NH3-N

Sincerely Lasse

I’m done - you keep bringing up extraneous issues.

Either they used the wrong measurement units or their results show that clownfish tolerate ten times the ammonia that I KNOW causes issues with that species.

 

[Lasse]

This is my last post according to this issue in this thread. Its impossible to discuss with a wall.

The main part in this discussion is if the report I attached in post 15 (Ammonia and nitrite toxicity to false clownfish Amphiprion ocellaris) - is a flaw or not. My answer is not - it reflect and is in line with many other reports about LC50 concentrations of NH3/NH3-N for marine fishes. I quote a part from an article from D.J. Randall and T.K.N. Tsui named Ammonia toxicity in fish in post 27. (D.J Randal was one of the most respected fish physiologist in the world - he died 2004) I will comeback to this article later on

The quote - my bold

The average of the mean acute toxicity values for 32freshwater species is 2.79 mg NH3/l compared with 1.86mg NH3/l for 17 seawater species, taken from data reported in the USEPA (1984, 1989) reports, respectively

Do this mean that I say that LC50 concentrations is safe levels in our aquariums - absolutely not of different reasons. One obvious reason is that LC50 is a population parameter - at this concentration 50% of the tested population will die in x hours. The general consensus among toxicologist is that around 10 % of the LC50 concentration is safe on an individual level. I earlier agree with Jay that for normal aquariums (Temperature - 26 degree C, salinity 35 PSU and pH 8. that around 0.8 mg/L TA (Total ammonia - NH3+NH4) can cause harm. It correspond to around 0.05 mg/L NH3 (close to Seachems upper limit for alert when using their free ammonia equipment)

But even if we use the 10 % rule on this study that say around 1.06 mg NH3- N as an acute toxic respons - 50 % of the population will die (LC50-24H ( 1.28 NH3) we will be higher than 0.05 mg/L NH3 and in the article of D.J. Randal (I mentioned before) he explain why the accepted testing method for LC 50 may be inappropriate. In the Abstract he says

Present ammonia criteria for aquatic systems are based on toxicity tests carried out on, starved, resting, non-stressed fish. This is doubly inappropriate. During exhaustive exercise and stress, fish increase ammonia production and are more sensitive to external ammonia. Present criteria do not protect swimming fish. Fish have strategies to protect them from the ammonia pulse following feeding, and this also protects them from increases in external ammonia, as a result starved fish are more sensitive to external ammonia than fed fish.

Full text attached



Sincerely Lasse

 

[xzt]

In my view, the focus of the two discussions is not the same. One is stating that the research methodology is scientifically sound, while the other is stating that the experimental results do not align with their own experience. The two are not contradictory.