[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Ammonium/ammonia
Hi Susan etal. I just wanted to mention that cycling a tank at a
pH below 7 is not necessarily safer: while it's true that relatively
non-toxic ammonium predominates such pHs, nitrite toxicity _increases_ at
lower pHs. Why? Because nitrite and nitrous acid exist in an equilibrum
similar to ammonia/ammonium. Nitrous acid predominates at pH below 7 and
is much more toxic than nitrite, because it is non-charged and therefore
does not require ion-transport channels, its passage through the gill
epithelium is not inhibited by competing ions (such as Cl-) etc.
Andrew
~^~
~