Leave block pier cells empty?
I'm building a 16x24 shed/shop and someone told me not to fill the block cells with dirt because it can freeze and bust the block so I'm wondering if they can be left empty. The piers are 3 block high on 6" footers, also I live in Georgia so theres not as many freezing nights though there are some. Filling the cells just isn't in the budget. Would filling them with rock(gab-rock and dust used under roads) be a bad idea? I can get it free off the job. The shed will have wood working tools( table saw jointer, planer, bandsaw,collector,which are 200#s each ,and hand tools. Thanks for any help! Hope there's something else I can do because someone stole my trolling battery and ext cord last night. So I need this built asap