My xenia are doing awesome and I don't think I have a nutrient rich tank. I feed very lightly and I run my skimmer all the time. My ammonia, nitrates and nitrites are all 0. Xenia seems to be really hit or miss. Some people with lots of SW experience have trouble keeping Xenia alive and some "newbies" like myself have great success with it.
If your live rock was already cured when you got it, you shouldn't have a cycle.... or if you do it should be really small. I didn't have a cycle when I upgraded my 46 gal tank to my 120 gal because I used the same rock. If I had left the rock from my 46 gal out of water for a few hours though I would have expected a small cycle because there would have been some die off on the rock while it was out of the tank.
If your live rock was already cured when you got it, you shouldn't have a cycle.... or if you do it should be really small. I didn't have a cycle when I upgraded my 46 gal tank to my 120 gal because I used the same rock. If I had left the rock from my 46 gal out of water for a few hours though I would have expected a small cycle because there would have been some die off on the rock while it was out of the tank.