Charles Harrison <charles at inkmkr_com> wrote:I kn ow you mean pH will be low in the para below:
At 8:31 PM -0800 11/24/04, Wright Huntley wrote:
>> Hi all, Some recent apparent disagreements, here, prompt me to ask >> what the definitive answer really is.
>> My understanding is that ammonia (not ammonium ions) and nitrites >> are toxic to our freshwater fishes. Ammonia damages baby fish gills >> at levels down around 5-8 ppb (yeah, that's parts per billion),
> And yet our Killies do well in a peat brown water which may be > several % ammonia/ammonium . . .
If it is peat brown, the pH is unlikely to be high enough that anyBoiling and rinsing peat could remove nitrogenous compounds, some of which may be fertilizer added to peat pellets, if you use those. I am not sure of these ammonia binding sites that are competed for by Ca and Mg ions. What is the evidence for that?
significant fraction is as ammonia, and ammonium ions are as harmless as
chloride ions. [Ammonium/ammonia test kits are likely to measure the adsorbed ammonium/ammonia at the CEC sites, too, which probably cannot harm the fish.]
That said, I never knew about the ammonium in peat, as I always boil and repeatedly rinse my peat and all the ammonium sites are replaced by the Ca and Mg from the harder tap water. :-) The nitrogenous stuff all went down the drain. This seems to keep all the best anti-bacterial qualities of the peat but reduces how "hot" and reactive it is. [Most of the lime added to virtually all agricultural peat, but not on the label, is also washed away.]
Nitrates are non-toxic enough that nitrate toxicity is not even discussed in one modern Fish Medicine text that I have.> > Hydration and hydrolysis and ionization and free reactive molecules > would answer your questions Wright, along with life form specific > susceptibilities. So we need ionization constants, dissociation > constants along with susceptibility to explain all this water > chemistry.
What would help we non-chemists is a guideline as to when
nitrates become toxic to killies at what temperature. That is what I haven't been able to find. My own experience has been that nitrates are harmless in surprisingly strong doses, as I have ODed planted tanks with KNO3 any number of times without seeing any fish stress. Maybe I failed to notice a reduction in eggs or fertility. I'm not sure.
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