The nitrogen cycle does contain bacterium which break nitrate down into N2 and oxgen atoms to complete the nitrogen cycle, and also of note... unlike terrestrial plants, aquatic plants greatly prefer ammonium and nitrite instead of the nitrate and will only begin to utilize nitrate after the water has been depleted of ammonium and nitrite (levels below .02mg/L) This places them in direct competition with the BB colonies you are trying to build up.Nitrate won't go down without water change or consume by plants.
The nitrifying bacteria are also competing for dissolved oxygen against the bacteria which break down organic matter, and unfortunately are not as efficient at extracting this dox from the water as the organic "eaters" are.
Also of great importance with repect to Ph...
Ammonia (NH3) - as we all know, is highly toxic to fish and can cause irreparable damage to gills and even operculums. Ammonia bonds with an additional Hydrogen atom at lower Ph and becomes Ammonium (NH4) which is non toxic to fish. So why acclimate a fish to high Ph's when the health benefits of the lower ph values within the standard range of acceptable ph for a given species indicate the lower ph is by far the safer route?
I always target the middle point of the bottom third of tolerated/acceptable range of ph for a given species or the lower (not lowest) ph range of overlap of grouping of mixed species.
For more detailed and highly informative easily understood discourse on this subject please go to the following:
http://www.skepticalaquarist.com/nitrogen-cycle
Any attempt to refute what I have posted will only further prove ignorance on the subject matter at hand.
And please don't misconstrue ignorance as stupidity.
Ignorance is easily fixed by the application of FACTUAL knowledge.
I am ignorant too! Until we know everything, we are all ignorant.
But remember... there is no cure for stupidity. Arguing the facts is kinda stupid.