It's okay as long as you don't start buying corals and fish. Add the rock and wait for the cycle to rise and fall. No big deal. It just takes longer if you add the rock in 3 or 4 phases over 2 or 3 months. Not many people can watch a tank full of rock cure for 3 months before adding a few fish. :mrgreen: Thats why everyone is telling you to add it all at once. Get it over and done with and the cycle should clear up in as little as a week or as long as a month.
I bought some of my live rock from a local reefer. It had been in his tank for years, so it was covered in coraline and loaded with pods and other life. (22lbs) Didn't cause a spike when I added it to the tank. Then I bought dry rock from a local store and that had dead organics on it. (17lbs) I rinsed and scrubbed until I thought I had all of it off. But it started to rot and get slimy after about 3 days in the tank. Massive spike. Rotting organics in the water. Had to do a 50% water change. Had to pull it out and cure it in a rubbermaid tub for about 6 weeks. Then I put it back in the tank. No spike. A couple months later, I bought more rock (another 22lbs) from a LFS and it was supposed to be cured. It was "partially cured" didn't smell awful, but still smelled like a wet dog. I put it in the tank and didn't see a spike. I can only attribute that to the DSB, cheato and already cured rock in the tank. It had to have absorbed any nitrates and ammonia, because I couldn't register anything on a test kit, even though the new rocks made my tank stink for a month.
I think it may be okay to add small portions of rock over time. Maybe 5 pounds here and there. Give it a month or 6 weeks and then add 3 or 4 pounds again. Wait another 6 weeks. But once you put animals in the tank--I don't believe you should try to add large quantities of rock anymore. If it's not completely cured, it'll cause a spike and mini-cycle. It can be rough on certain corals and inverts to endure repeated spikes and cycles. Kinda like you getting a bad case of the flu once a month for 6 months in a row. By the end of it all--you'll be so worn out, you may not live.