Hi Guys, may a wish you all a very Happy and prosperous new year I did my second water change on my new set up, (20.11.16) yesterday, the first last week after being advised to leave well alone for a month or so. I decided, rightly or wrongly to use my hand to waft around the rock to flush out any debris/detritus there. Most of what came out simply looked like powdery rock. I switch off all pumps during changes so it was a simple process of syphoning this off once it had settled on the coral sand then using my eheim vac to pick up anything left behind once I reached the level I take out. I noticed what I thought was an unpleasant odour whilst doing this. Checked out all parameters 6hrs later, all fine. Is this just what's left off the dead stuff from the cycle of the live rock or is it normal? I guess I'm also asking have I made an error in moving this debris from within the rock? is it a food source for the bacteria?