I recently moved my established aquarium from one room to another in the house. I had to remove most of the water so that I could lift the aquarium (with help!).
Once in the new location, I returned the original water to the aquarium and left the aquarium settle down for over six hours. At that time, the fish seemed to be happy and not showing signs of stress.
I added some new fish (three neon tetras and two fancy-tail guppies) to the aquarium - see this Q&A. The new tetras died very quickly thereafter. I had followed all the advice that I learned from the pet store and which agreed with most accepted internet wisdom regarding acclimatizing new fish to an existing aquarium.
Should I have waited longer to allow the fish to calm down more following the move?
EDIT: Further information follows regarding my set-up. The aquarium capacity is 100L, and the original occupants were three guppies, one angel fish, two albino catfish and the three neon tetras. There were two plants. The aquarium was well-established prior to the move - i.e. it wasn't part-way through a cycle. I am not able to test water quality.