Well, if they are still eating aggressively, you do not have anything to worry about immediately. You need to get those nitrates down though. A smaller water change will not do much for you. You need to do a series of larger water changes (30% every 3 to 4 days to get them down).
I would also be sure to use garlic and vitamins in all of the fish's food.
Kent RxP is not safe withlionfish, scorpionfish, many inverts, and I am not sure if it is totally safe with live rock either.