I agree with a previous post that the source of your ammonia is the live rock that was in storage for years. I personally would dispose of it and get new live rock from your local store. After you get rid of the live rock, I would do a 50% water change to get the nitrates down to 40ppm. A couple of days later, I would do another 50% water change to get the nitrates down to 20ppm. For a fish only tank, 20ppm is acceptable. For a reef tank, it'll be a little tougher since you'll need to keep nitrates at around 5ppm. Remember, you can only cut nitrates in half by doing a water change of half the volume of the tank. Hope this helps you.
