Caliban07
Aquarium Advice Addict
Source: Interpreting Water Analysis Test Results
[FONT=arial,helvetica][SIZE=-1]"In fish, ammonia represents the end-product of protein metabolism and what is important is whether it is present in the un-ionized form as free ammonia, [/SIZE][/FONT][FONT=arial,helvetica][SIZE=-1]NH3, which is toxic to fish (both freshwater and marine) at >0.03 mg/L (ppm),[/SIZE][/FONT][FONT=arial,helvetica][SIZE=-1]or in the ionized form, NH4+, in which it is innocuous. The relative concentration of each is pH and temperature dependent. The higher the pH, the more of the NH3 will be present. Ammonia can block oxygen transfer in the gills of fish, thereby causing immediate and long term gill damage. Fish suffering from ammonia poisoning will appear sluggish and come to the surface, as if gasping for air. In marine environments, the safe level of NH4+ is between 0.02 and 0.4.[/SIZE][/FONT]
[FONT=arial,helvetica][SIZE=-1]The USEPA recommends a limit of 0.02 ppm as NH3 in freshwater or marine environments. Total ammonia levels, at this limit, can range from 160 ppm at pH 6 and temperature of 5 degrees C to 0.06 ppm at pH 9 and temperature of 25 degrees C."[/SIZE][/FONT]
This is just a reiteration of what we have been learning about NH3 (free ammonia)
[SIZE=-1][FONT=arial,helvetica]The US Environmental Protection Agency has a limit of .02ppm NH3. But here in aquaria we basically enforce much lower limits...[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]Serious questions, showing how "green" I am about a fish-in cycle, and bad parameters in general.[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]a) When fish die to assumed bad ammonia levels, how sure are we that it was the ammonia and not the nitrite?[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]b) Why is such a low level of TAN acceptable for fish-in cycling when free ammonia at that amount is so low? I still believe low ammonia means a cycle that takes FOREVER. Plus the forum is making people WC every day.[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]c) How often do we get reports of fish dying where we are 100% certain it is ammonia?[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]d) How many people actually understand the free ammonia part of the API ammonia reading?[/FONT][/SIZE]
[SIZE=-1][FONT=arial,helvetica]Did you happen to see the thread in this subforum with the betta in the cup? Where the ammonia was off the charts? I mean the free ammonia in that cup can't have been that bad. Everyone was shocked the fish was alive, but I kind of wasn't because of all we have learned...[/FONT][/SIZE]
No i missed that thread. i think we now realise ammonia toxicity is dependant on variables that if kept under control are safe for our fish.
a) This was where my next trail of thought was heading. How much nitrite is produced from 1 unit of ammonia and what are the toxicity levels of nitrite.
b) I dont believe water changes are necessary. I do one when fish in cycling and thats to add some phosphate as i read about the block a while back. I think you could easily not do any. Especially at lower doses as we now know that alkalinity and dissolved oxygen uses would be even less thus WC would be less important.
c) We dont. Could it be that fish during a cycle are susceptible to low DO as the bacteria are using it to establish a colony. Could this cause gasping at the surface as opposed to ammonia burn? There may be other reasons we havent thought of yet.
d) Not many but i feel that this should be enforced to a newbie. At least that way they can do what they want with the info.