do you need a fish in a tank for it to be cycling? i have atank that is fully cycled but i want to add more live rock and im not sure if i need the fish in there to make the nitrites or nitrates, or whatever.
no, fish in a tank while cycling is bad, and anyone that tells you otherwise doesnt respect life very much, the ammonia and such produced by fish burn their gills, and does other damage even though a fish can be tough enough to survive it, its not a great idea, if you put live rock in a tank, it will naturally cycle all by it self, you will have die off, which causes ammonia, and thats what your looking for to start the cycle, if the tank already has rock in it, depending on how much you add, you might experience a very slight cycle, but its still better to do it without fish if you can.
the damsel will be fine, but just remember that for the future, everyone always throws a couple damsels in to cycle a tank, but its not nessesary. and after you have all the rock in, its impossible to get the darn fish out!
Does cycling affect corals? I just moved stuff into my 90 and unfortunately one fish has been affected. Does it affect corals though? I do have a few in the tank already and I plan on adding more rocks.
yes it can effect the corals.
the levels in the tank could possibliy go in to a moini cycle and the level could good weird on you. but if you have a good amount of LR in the tank already you may be fine. also if the lR is coming precured or out of an existing tank ( a freinds /LFS ) you may not see anything change at all..