Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Well, no, you do not have to add ammonia over and above what the soil supplies. For 3-4 weeks it keeps on producing ammonia, and feeding the bacteria. Do water changes to keep the level of ammonia in the right range to grow the maximum bacteria. Your water change will get the ammonia down to or under 1 ppm, then the soil adds more ammonia to about 3 ppm, then you do another water change.
Aquasoil also has a tendency to remove the carbonates from the water.
This drops the pH.
Nitrifying bacteria do better with higher KH and higher pH.
Add potassium bicarbonate or sodium bicarbonate to keep the KH at least 3 German degrees of hardness, and higher is better. The bacteria will grow best if you can keep the pH at least in the upper 7s, and into the 8s is really good.