Kurt beat me to it. Good quality fully cured LR
form a local source really does give you a cycled tank in almost no time at all. I still prefer to add a bit of ammonia and cause a mini-cycle prior to adding any livestock. That just for the warm fuzzy feeling of seeing spikes and back to zero on all tests as insurance that the tank can handle a new bioload.
Congratulations! You are on your way. I will continue to caution you to go SLOWLY form here on out. Add more rock in small quantities (5 pounds at time?) till you get to your goal. Test the water every day for a week to see if you get any spikes, then add more rock. If you never get a spike you can probably increase the amount you add the next time IF it comes from the same batch at the LFS
AND they have not added any new uncured rock to that system. Caution, (trust but verify) is the best policy.