When I upgraded mine, I started with new sand as well...was worried there might be "stuff" trapped in my old sand that I did not want to release into the new tank.
I did use all of the water from the original tank, and the live rock of course.
As for the new live rock...can you slowly add it to your exisitng tank while you are building out the new tank? perhaps 10 lbs here and 10 lbs there...that way it can truly cure in your existing tank, which might be better suited to handle any potential spikes. Just a thought.
My new tank never really cycled after the upgrade - thanks to the water and rock from the old tank I think. I doubled my volume from 45 to 90 gallons by the way. I did notice that even though I did not have the spikes...the reef was not as vibrant as it was in the older tank for about 60 days (It looked good mind you...but not as full as it typically does)....eventually it caught up though...and now the coraline algae is back on the glass, etc. and it looks great. Also, for the first month, I did weekly 20% water changes just to be safe. Typically I do them b-weekly. |