When do you add what harware when a new tank is cycling?

I have started a 55g tank cycling with live rock. The heater, powerheads and filter are running, but when should you add a skimmer? When do you need lights?

 

Skimmer can be started whenever you want but is commonly started after the tank cycles. Same goes for the lights except no need until you have corals and fish.

 

You really dont necessarily "need" a skimmer at anytime, but if you choose to run one I would start it up after the cyle ends. As for lights, you only need those when you have something that needs/wants light. So whenever you get fish, coral, etc....

 

I bought the live rock from the LFS just as they got a shipment in. They said less than a week ago it was most likely in the ocean. It was covered in dead material so I'm worried that I need a skimmer to remove some decaying junk. At 2 weeks in, my ammonia test was off the scale.

 

In that case, yes go ahead and fire up the skimmer! It certainly won't hurt anything.