I don't power pack. Those are mostly for rehabilitating horses or horses with unknown deworming histories as it has a slower kill off time. I just use Quest plus (dosed to weight) twice a year spring and fall to kill everything including tapes. You should not use Quest on debilitated horses thus power packs. Quest kills the things a power pack aims for (typically encysted strongles) in one dose. Way cheaper and the most effective dewormer on the market so it can't be given to horses with unknown deworming histories due to the risk of a large die off if the horse is heavily parasitised. This is my vets advice.