Upgrading tank from 45g to 90g

[ColinPrice]

Hello all. I'm looking to upgrade my 45g FOWLR tank to a 90g FOWLR tank until I can make it a reef tank in a year or two when I get the funds for it.
My tank includes:
2 powerheads
backpack protein skimmer
30lbs of live sand
45lbs of live rock
2 false clowns
1 flame angel
1 ornate wrasse
1 scrubble rabbitfish

The 45g tank is now on the stand where I'd like to put the larger 90g tank ( I built it for a 90g so it's very stable) What is the best method to change tanks? I'd prefer to not have to have both tanks running at the same time as the 45g will have to be on the kitchen floor. Can I use the live rock? Any of the sand? It'd be nice to not have to buy everything new to save me some money, but I'm also hoping to not have to deal with the long cycling period of a new tank as well. Any help would be appreciated.
Thanks in advance!

 

[4deepwater8]

I am no expert, but I just did the same thing you are going to do. I used the live rock from my old tank and ran it for a week just to get it going and then added my fish and other creatures. Everything did great, I didn't lose anything.

 

[gillies]

Why is 45 to 90 gal an upgrade? Upsize?

Mix up 45 more gal of water and switch em out. Done. Seriously.