IMHO, the answer is no, at least not enough for you to worry about. Arimidex is a good idea for almost any cycle, as keeping estrogen in check is of utmost importance. I've used just nolva before on a test only cycle, and I did notice some more water retention than when I used arimidex. Some people might tell you that some estrogen is actually good during a cycle for the joint relief/lubrication, but I don't put much stock in this. The majority of gains while you're "on" will actually come from your kitchen, not the weightroom, so that's what you need to focus on. I think the positives from using arimidex far outweigh the negatives. So you might miss out on 5-10 lbs. of water weight with the a-dex, big deal! Who wants water weight anyway? Lift big, eat extra protein at all times of the day, and I seriously doubt that you'll be disappointed with your gains.
Good luck with your first cycle bro!