Whenever you let a tank go fallow for any period of time, you need to keep feeding the tank no matter what's in it. The added ammonia source will keep the bacteria fed at least to a small degree. A small pinch of flake, few sinking pellets or very small amount of meaty foods twice a week.
If you have not been doing that I would suggest you start and post the parameters of the tank. NH3
are going to be your only guide of if the tank need a "boost". After only a week you should be fine and with the current inhabitants it will make it a tough prospect to cycle the tank anew anyway.