In the three months that the soil stood in your livingroom, something else might have happened besides the airing out.
In the time the soil stood in your living room, no organic matter would be added to the soil. That means that the bacteria in the soil had 3 months to degrade the existing organic matter.
So the soil you used in your first tank could in theory have contained a whole lot more organic matter than the same soil you used in your new tank, 3 months later.
If your livingroom also has a higher temperature than the soil in the ground that would only let the bacterias work faster.
So, less organic matter, less bacterial production, less leaked ammonia and free N2 into the water....
Is my theory, its just that though, a theory... |