what to do with empty tank?

I have a 75 gal, non reef tank with just live rock and sand in it, no fish. Fish died awhile ago from ick, couldn't get to them quick enough. So, my tank has been sitting idle for about 3 months now. I have already treated the water for the ick. My question is, if nothing is in my tank, do I have to continue to run my protein skimmer and pump for the tank or can I just shut everything down till I can get more fish? I have not been getting anything to clean in my skimmer for quite awhile now.