I just have to clear up a few inaccuracies posted by Spoon25:
1) Performing a water change replenishes trace elements (to a limited extent), but it does not add nutrients to your system. Water changes take out nutrients, that's why we do them.
2) Reefs undergo substantial temperature changes, so a fluctuating temperature will not kill your corals. However, you should make every effort to match your temperature and pH and to aerate your water change water beforehand.
3) Anthony Calfo does nearly 100% water changes, and his thread resides
here.
Finally, it's too hard to diagnose a tank problem without listing your levels of ammonia, nitrite, nitrate, phosphate, pH, temp, etc. Also, the length of time your tank has been setup.
I get the feeling that you've set this tank up quickly. Your going to get a cycle even if the rock was cured beforehand, and you're also going to get a small cycle when you move around your liverock.