While you were cycling the tank (which I assume you did for a month), did you provide an ammonia source for your bacteria (either household ammonia, fish flakes, or a raw cocktail shrimp)? If not, your bacteria died and had nothing to live on; though you should have ammo in your tank now if that were the case.
If your rock was dead (ie, dry), you let it cycle for a month, right? If no rock at all...what are you using for biological filtration? A canister or HOB filter?
I would get canister (or 2 100mL bags) of Purigen and a bottle of Prime. Dose the Prime based on instructions and drop the Purigen into a high flow area. That will get your immediate problem solved. After that, it sounds like you definitely need to get some good bio filtration going.