there will be ammonia present whether the rock is cured or uncured---some of it will die off anyway
without a protein skimmer u r pretty much hopeless---also, any fish in the tank may be in danger
i'm nowhere near being an expert, and i hate to contradict s.reef because i've received much information from him/her (sorry
)---i've read to have the light on only when u r checking the progress of the curing process to prevent algae and diatom blooms