switching to a bigger tank

I switched from a 55 to a 75 in one day and had no problems. It went exactly as you state, except I don't know if I'd add all the old sand at once, as there may be pockets of unpleasantness. Probably just add a few scoops of the old sand to seed the new sand bed. If you need to use the old sand, I would rinse most of it, if it were me.

 

I just switched my 75 to a 125 and I just moved it all except I had crushed coral and went to sand.. have I little bit of of brown algee grown on the glass but nothing bad takes 5 mins with the magnet scrapereveything else doing fine did lose a cleaner shrimp but nothing else..

 

I had to do a similar procedure when my 55 sprung a leak. Using as much of the old water, rock and sand as you can will keep the tank fairly stable and you shouldn't lose anything. +1 on rinsing the old sand before adding it to the new setup, just make sure you rinse it with RO or treated tap water so as not to kill any the bacteria - don't use water straight from the tap. The other thing you can do "just to be sure" is get some StressZyme, Cycle, BioSpira or the like and dose your tank daily for the first couple weeks. Doing so will deffinately help control/prevent any amonia or nitrite spikes.

 

Take most of the water and rocks out ebfore you mess with any of the sand because you would rather not transfer what you stir up from the sand bed in the rocks and water if you can help it.

Good Luck

-Justin