So realize you are starting over everytime you move them. They need to get settled before they'll eat, this could take some time. Be aware that once settled the is a good chance one will start bullying the other. A pair of silver arowana rarely works, I would advise getting rid of one as you can always try to combine a pair when you are a lttle more prepared.
To help make them feel more secure add some floating plants, keep from wearing bright colors such as red, orange and yellow. Keep your movements around the tank from being sudden. Having a nightlite in the room will also help from being spooked at night. Best bet at this point is to not even feed them, in a few days when you see signs of them calming down try feeding floating pellets once a day. Remove uneaten pellets after a half hour or so. Turn the tank lights on and off on a daily basis, they need to get used to a routine.
Try not to panic if they are not eating. They can go quit a while without food.