Eh I have moved corals into brand new tanks. Doesn't apply to OP since his tank is Fowlr. But I actually find corals easier to move than fish.
If you have live rock you can transfer the live rock over, and transfer your fish right in. Monitor for a while, but the LR should have enough bacterias in them to allow you to add fish straight away. If you don't have LR, transferring the media from old tank and using Dr. tims or similar before adding the fish, is a good idea. You will want to add at least one fish straight away to feed the bacteria in new tank.