You will see conflicting opinions, just as whether you should change water or not during the cycling process. I do not use a skimmer, but many do. I did change water during the cycle. I realize this can cause the cycle to take longer, but I did not want to stress and kill any more of the creatures in the live rock than necessary. Not changing water may prepare the tank to handle a larger bio-load, but I feel that livestock needs to be added gradually anyway. You just have to keep reading and do what makes the most sense to you. Both methods work, so you needn't worry about it. Good luck.