Do you have a TDS meter? If you do, check TDS on the two tanks and see how big a difference there really is. If the TDS is not vastly different you'll be OK to move them. If there is a big difference, then a smaller container can have water added from the new tank until the TDS is a closer match.
Just to be safe.... They are all "sleeping" in the box and I have an airline tube dripping water into that box right now :)
I waited until the sun is down, cover the tank to make it even darker then they slept about 30mins ago. Got all the caridnals and discus pretty easy that way.... they were not even moving when they are out of water hahaha
My sterbai cories on the otherhand..... impossible since they are kind of nocturnal... I just switched the light on and hope that the cories will go to sleep... I will accimilate them separately from these fish and move them later. all the hiding place and plants make it way too hard