Printers should also go back in their original boxes. Remove toner or cartridges from laser or inkjet printers and insert a piece of paper in the platen of pin printers. That's why it's perhaps best to find a new home for your finny friends. But if you feel compelled to try, here's what to do. Put the bags in an insulated container.
Large fish can go in sealed buckets.
Try to keep the temperature as constant as possible. Moving the tank is a bit less stressful. You'll have to drain, empty and clean the tank. For short moves, you can keep your plants in plastic bags with some water in them. Pumps and heaters should be carefully wrapped and packed, and the tank itself should be reinforced with masking tape, wrapped, then placed in a box with plenty of Styrofoam peanuts.