Ammonia Toxicity, Do I Get It Now?

[Meeresstille]

First, you need to know that English is my second language. It is sometimes a little hard for me to follow when things are being said in technical speak. Also to save myself the trouble of having to translate I rather not do research in my own language, it is easier to learn everything in English.
 
It's been 2 1/2 years since I started up my first aquarium. Up until now I've always believed that an ammonia reading of .25 on our home liquid test kits was already toxic enough on an ongoing basis to cause long term damage on our fish's organs. 
 
Looking into it further on a few sites on google yesterday, after taking part in a few threads here about it that contradicted what I'd understood about ammonia, I read about pH and temperature having an effect on the toxicity, or rather the amount of ionized ammonia, the less toxic form also known as ammonium, that is part of the total amount of ammonia.
 
I think in our home aquariums most of us see pH levels somewhere between 6.5 and 7.5. So at first I thought the severity of acidity and alkalinity that we see in our home aquarium is what is having an effect on the amount of ammonium, but after reading about fish farms and the cycles their water goes through in a 24 hour period I understand now that the pH fluctuations are much more severe, they're talking about pH levels as high as 9 for example. So, now it makes a lot more sense to me why the pH we normally see in our home aquarium will only marginally effect the amount of the toxic form of ammonia in our water.
 
What is responsible for these fluctuations is the carbon that is being produced by the fish and how that effects the acidity of the pH not only during the 24 hour cycle where fish and plants produce more of it during the day, but also how as the fish grow (on fish farms) their larger bodies near the time of harvest will of course produce more. Then there are the fluctuations of temperature during the day/night periods.
 
The fish farmers take readings during different times in the day and have something like a conversion table where they look at the amount of ammonia their readings show, along with the temperature of the tank and the pH and the calculations show them what the actual amount of harmful ammonia is in the water.
 
So, I guess that means if the reading of ammonia after such a calculation comes back as .25, that is what they are talking about when they say that long term exposure to ammonia of .25 causes organ damage in fish!? And that's why, in simple terms, when we see ammonia in our home aquarium there is no need to panic about our fish's health at a reading like that, but know and understand why we see ammonia and not to let it get too high!
 
Thank you for reading this far, I hope I did not make myself look stupid, and please feel free to correct or add!
 
 

 

[TwoTankAmin]

pH is the key to knowing how much of the ammonia is in the toxic NH3 form aka unionized ammonia. This is what causes the harm. Temperature has about 1/10 the effect that pH does. In order to know how much of the ammonia your test kits shows, you must use the pH and temperature in a formula that tells you.
 
It is a mistake to assume what you see in fish farms is what happens in tanks, for one the stocking on fish farms is insane compared to tanks. Next, they are outdoors-sunlight can not be controlled the way tank light can. Think of the difference between how you would care for your tank vs a 2,000 gallon pond. Then realize that fish farms calculate things based on surface area in acres, not gallons. (An acre is 4,047 square meters.) They cannot do water changes.
 
Our tanks do not swing wildly in pH. Yes there is variance during the 24 hour day, but it is nothing like what is seen in huge aquaculture ponds.
 
When I first began using pressurized co2 in a high tech planted tank I really wanted to avoid needing a pH controller but was preapred to run an airstone at night to clear the co2 from the water. So I sat up til the wee hours testing my pH to see if it would drop a lot at night with the co2 still running. The change was not great and for 10+ years I ran my co2 24/7 and never had any pH problems.
 
As to how much NH3 it takes to cause harm, the answer is it depends. Different fish have higher or lower tolerance for ammonia. Not only does this matter, but so does the age of a fish. Eggs and fry with their yolk sac are very tolerant of ammonia. free swimming fry are very sensitive, juveniles are again hardy and then as fish age into and through adulthood they become increasingly susceptible. But as a rule, under .02 ppm is pretty much safe for all aquatic life and .05 ppm is a red line. At this point ammonia is causing harm and the higher it goes from here the worse it is. But the level of ammonia is not the sole issue in terms of harmful effects. Duration of exposure is also relevant. At any given level, longer exposure is normally more harmful than shorter term exposure.
 
But you missed one other important consideration. When we talk about cycling a tank it is a reference to the nitrogen cycle. Ammonia is NH3, that is, 1 nitrogen and 3 hydrogen. Nitrite is NO2, that is 1 nitrogen and 2 oxygen. Nitrate, NO3, is 1 nitrogen and 3 oxygen. All through the process one thing remains constant- nitrogen. In most of science they focus on the nitrogen not the other components. To do this they measure only the nitrogen ions. The results are expressed as ammonia-nitrogen or NH3-N, etc. etc. Even when measuring total ammonia (NH3 + NH4) it is as TAN, aka total ammonia nitrogen
 
The problem is our hobby test kits measure more than nitrogen ions, they measure all the ions. So, if the scientist and the hobbyist test the same water for ammonia, the scientist will get a reading of 1 ppm and the fish keeper will get a reading of 1.28 ppm. And this difference magnifies as the nitrogen works through the cycle. 1 ppm of nitrite-nitrogen will test as 3.28 ppm of nitrite on the API kit, while 1 ppm of nitrate-nitrogen will show up as 4.43 ppm of nitrate on most hobby kits.
 
This doesn't mean hobby kits are wrong, they just use a different scale. Think of it as temperature in C vs F or distance measured in miles vs kilometers. What is important is to know which scale is being used. Rarely in the hobby do we see this sort of information made clear. The cycling article here took all of this into account.
 
What this does mean is that it is not possible to say that .25 or .5 or even 2 ppm of ammonia as determined using a hobby ammonia test kit is harmful to fish or not. One must figure out how much of those ppms are NH3 to know the answer.

 

[Meeresstille]

Wow, TowTankAmin, thank you so much for taking the time to answer. This is extremely informative. Only read it once so far, and I will need to study it some more, lol!  Again, thanks! 

 

[Meeresstille]

OK! I hope I wasn't the only one befuddled by this, and that this thread may help others as well. 
Here's what I understand:
 
1) Our home test kits measure TAN (NH3 + NH4 combined). 
2) The actual toxic amount (NH3) depends on a lot of different components such as temperature, pH, even ionic strength and air pressure!
3) A difference of 1 point in pH up or down, can change the amount of NH3 10 times into the negative or positive.   
4) It is quite complicated to work out the actual amount of NH3. There are calculation tables and you may have one that came with your liquid test kit. Roughly, at a pH of 8 under normal tropical aquarium temperature settings a Total Ammonia Nitrogen amount of 2 ppm contains somewhere around .1 ppm NH3 (Ammonia in toxic form). According to my calculation table a water change at that level is advisable. A 50% water change would bring the NH3 down to .05 provided the water change does not increase the pH.
5) It is wrong to say long term exposure to ammonia levels at .25 can cause organ damage in fish because we don't know how much of it is NH3. 
6) And NH3 of .25 would actually be lethal!
 
Thanks for your patience TTA, it took me a while, but I think/hope I've got it now! 

 

[TwoTankAmin]

1) Our home test kits measure TAN (NH3 + NH4 combined). 
No, they measure total ammonia not total ammonia nitrogen.
 
2) The actual toxic amount (NH3) depends on a lot of different components such as temperature, pH, even ionic strength and air pressure!
Forget everything but pH and temp.
 
3) A difference of 1 point in pH up or down, can change the amount of NH3 10 times into the negative or positive.
No- changes in pH  affect NH3 levels about 10 times as much as changes in temp.
 
4) It is quite complicated to work out the actual amount of NH3. There are calculation tables and you may have one that came with your liquid test kit. Roughly, at a pH of 8 under normal tropical aquarium temperature settings a Total Ammonia Nitrogen amount of 2 ppm contains somewhere around .1 ppm NH3 (Ammonia in toxic form). According to my calculation table a water change at that level is advisable. A 50% water change would bring the NH3 down to .05 provided the water change does not increase the pH.
Here is a link to a calculator http/www.hamzasreef.com/Contents/Calculators/FreeAmmonia.php You need to bring the NH3 level well under .05 ppm. That is the danger level and you would want to get well below it to allow for any increase in ammonia.
 
5) It is wrong to say long term exposure to ammonia levels at .25 can cause organ damage in fish because we don't know how much of it is NH3. 
No- long term exposure to ammonia is never a good thing. What we are discussing is exposure during fish in cycling where exposure times are relative short term. The key is NH3. In an 80F tank with a pH of 8.6 being cycled with fish for rift lake cichlids a .25 ppm reading for total ammonia will be harming fish.
 
6) And NH3 of .25 would actually be lethal!
It would for any fish that could survive the run up to that level.
 
In an established tank there should never be measurable levels of ammonia or nitrite. When there are you do not worry about how toxic it is, you find the cause and correct the problem ASAP. There is a big difference between what is OK during a fish in cycle and what is OK in an established tank.

 

[Meeresstille]

Oh, I was so depressed last night after reading your answer! 
 
Here are my thoughts today:
I know that Ammonia would/should not be seen in a cycled tank. If it were to show up it would be a sign of trouble with the bacteria in the filter. I know that Ammonia is something that is an issue for uncycled tanks, but the purpose of my thread was not about that. It was becoming clear to me by reading opposing advise that I was missing something when someone wrote about a problem with their tank and their ammonia levels, I had always believed pretty much any amount is a bad thing for any tank, but as it turns out, it is depending on many factors, and these factors will determine at what point ammonia becomes a problem.
  
1) So, when you said " Even when measuring total ammonia (NH3 + NH4) it is as TAN, aka total ammonia nitrogen" is this done by the scientists only, not with our home test kits!?
2) yup
3) Your explanation confuses me, can you explain the difference in what I said compared to what you said (temperature aside)?
4) yup
5) What I meant was that as a blanket statement it would be wrong to say this! There are too many variables to consider, like does the tank's pH sit at 8.6 or at 6.0 or anywhere in between... 
6) yup
 
I apologize if I seem dense, I did learn a lot from this though, and am very grateful for your help!