Can I safely switch tanks?

[chaoscat]

I just bought a 90 gallon tank to move my Cichlids into. This frees up a nice 55 gallon tank and stand. I'd like to move everything from my 40 gallon reef tank into this. BUT, it's a little scary to contemplate. I'm not sure just how dangerous this is. My reef is setup with a Jaubert plenum and I would duplicate this in the 55 - re-using the established aragonite live sand from the reef, just adding more to fill up the extra space. My thoughts were to:
1. Drain most of the water down into an old 30 gallon I have sitting around, saving the other 10 gal in buckets.
2. Move all the live rock and corals down into that as soon as I have enough water to keep them covered
3. Scrape out all the live sand and transfer that over into the 55
4. Add back in the original 40 gallons of water.
5. Put the corals and live rock back in
6. Slowly bring the tank up to full over the course of the day.
So, anybody know how risky this is? or can I do this without causing total chaos and destruction to my reef.

 

[matt b]

sunds like a good plan but im not the 1 to ask if its ok

 

[rcoultas]

you can do this but it will be a slow and tedious task.
when you transfer the sand you are going to stir up a lot of stuff! you'll need to let that settle until you can see well enough to place your rock etc. After it is all placed and the majority has settled you can re-introduce your fish. You'll need to monitor your water parameters closely for several days after as the bacteria colonies will have been totally disrupted (excepting the sump colony)and may not immediately handle the bio load (ammonia may spike a little thus requiring a small water change) Other than that it's business as usual. I recently did this to one of my tanks without any problems at all but it took two days to do.