Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
If you move plant's as well to new tank ,there may not be much of an ammonia spike.
Otherwise, bacteria will multiply rather quickly to adapt to available food (fishes?)
Could be only a few day's of monitoring the water, and bacteria colony would be sufficent for number's of fish from old tank assuming that is all that's added .
If adding new fishes as well.. then a bit longer.
Still beat's four to six week's or longer. IMHO