waterdrop
Enthusiastic "Re-Beginner"
Yes, wait until its going off the scale.How much nitrite am I waiting for to reduce my ammonia dosage to 2ppm? Do I need to wait for it to go off the scale? (5+ ppm)
migthegreek, on 16 November 2009 - 08:27 AM, said:
When I add more ammonia, what amount am I going for? I read in the beginners' Fishless Cycle thread 3-4ppm but you recommended someone add 2ppm during the nitrite spike or something in a different thread. Can you explain this for me?
JustFrozen replied: this is a great question. a lot of times we're told what to do but not necessarily why, and this is something i've been wanting to know myself, as i'm currently in the nitrite spike phase. my understanding of it is that during the nitrite spike phase, the only goal is to get enough nitrite-processing bacteria to get the level of nitrite down to zero. if you keep dosing the full amount of ammonia, it's only going to keep the nitrite off the chart for longer. really what you want is to just give enough ammonia so the ammonia-processing bacteria dont die off. it probably wont hurt the cycle to add the full amount but there's already plenty of nitrite in the water without adding a full 5ppm of ammonia every day, so i guess you are just delaying the day that you will see the nitrite hit zero. WD or OM or someone please let me know if this is correct
JF, I don't think we ever attempted to answer the deeper question you had here of "why?" The answer is as follows: Any time your test finds measurable nitrite(NO2) it of course means there's more than enough food to "grow" that particular species-specific colony. So even a little nitrite would be sufficient to help the N-Bac colony get larger. But since the A-Bacs put out 2.7ppm NO2 for every 1ppm of NH3, we have excess NO2 sitting around that's not really needed. The too-small N-Bac colony will, eventually, work its way through the excess but as it does that it will be further multiplying it (x3.6) and so the final nitrogen product, NO3(nitrate), will always be in excess.
The thing about nitrate ion(NO3-) is that when it is in solution in water, it will exist in its different resonance structures and although about 93% of it will be in the ionic state with a minus charge, about 7% will find a naked hydrogen proton (H+) and form HNO3, which is Nitric acid, a very powerful acid (yes, the wicked looking stuff that fumed in chem class!) Of course, its only a tiny amount and is distributed in a lot of water, but nonetheless it has a powerful ability to lower the pH of the tank water. This is the reason that nitrification lowers pH any time it is in process (which is always, to some extent, in a tank with a biofilter.) During fishless cycling, when we (on purpose) simulate a fish stocking that's larger than the tank can properly handle, the acidification from excess nitric acid can be quite pronounced and will nearly always drop the pH to the point where the autotrophic bacteria will stop processing, in tanks with insufficient KH.
~~waterdrop~~