Upgrading from a 40 Gallon to a 75 Gallon

[JtheNomad]

With the downturn of the economy ive been seeing a ton of tank sales and have been considering an upgrade. How difficult would this be to do? I'd probably buy the new tank and get new Sand substrate because I want a more natural white or tan sand but ive heard that your substrate has a good amount of bacteria in it. I have about 7 Green tiger barbs, 4 Mollies, 4 Corys, a single Rainbow Shark and clown pleco, and various invert's. So any tips or suggetions on how to properly do this.

 

[SaraB]

So what I did when I upgraded is used the substrate from my old tank but added the new sand on top. After adding the decorations and everything else (again from old tank) I added the fish and did a fish in cycle. It only took a couple of days.