ya i switched all my foot long bichirs to massivore and sinking carnivore when i found out how bad live can be for their health. I only give live as a treat once in a while now.
When you buy a fish they wont eat for 3 or more days.
But at the same time you need go hiding spots for your fish or they will get so stressed out they will die.
So ya if you have decorations just give it a day or two ( i would try bloodworms first )