Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I would not wait several days.
Sit the 2 tanks side by side and move everything over.
Monitor it, of course, and be ready to do some water changes if needed.
You will be losing some bacteria that are living on the substrate, but not much.
You could add a few extra floating plants, then remove them a little at a time over a few weeks. Plants that float are not dependent on the CO2 in the water, so are better able to take in any extra ammonia that might happen when you lose that bacteria in the substrate.