Gawsh. Wish I had all the scientific eloquence needed to say this but I don't.
All I have is personal experience. It took a mighty big hammer to finally pound this into my head: NO AMMONIA NEEDED TO CYCLE A PLANTED TANK.
This was a brand new concept to me and it sounded way too good to be true.
Right off the bat, (10/21/04) I put 2tsp. ammonia in my brand new 75G planted tank (2tsp. was the amount needed to bring ammonia to a reading of 5).
It took a couple days for plants to remove ammonia, but soon they did.
After that, every 12 hours ammonia was back down to zero, and every 12 hours I chugged 2tsp. back in. Tank went thru nitrite spike. Ammonia kept dropping to zero. And I kept adding back that ammonia.
...However, by day 16 of my persistantly dumping ammonia back into this poor tank, I started to notice that my ammonia was not popping back to zero as efficiently as before. Nitrite was still at zero, but only for awhile. and I was getting Nitrates. I did a huge water change and of course dumped in more ammonia. I was sure the good bacteria would starve and die if I did not feed ammonia.
Wish I would have left well enough alone at that point.
At that point, it seems like tank just stopped using ammonia up very efficiently at all. For the next 4 or 5 days I was getting .25 ammonia, nitrites came back, and nitrates around 80 - every day. Obviously I am quite inexperienced. Maybe this is all normal behavior, but after getting used to seeing zero ammonia and nitrites, I was terribly disappointed to see those new higher readings every day. I decided I was doing harm by adding ammonia.
I did another water change and stopped adding ammonia.
That was exactly 2 weeks ago, today.
As of today, ammonia and nitrites have stayed at zero. Nitrates are 5.0-10. My last water change was 2 days ago.
Tank is thriving. And I am happy.
I will never, EVER use ammonia to cycle a planted tank again. Never.
~Behold the Savior of mankind,
nailed to the shameful tree.
How vast the love that Him inclined,
to bleed and die for thee.~