Switch a 55 gallon over to a 125 gallon

[scotts2002]

I have a well established 55 gallon tank that has approximately 75-85 pounds of live rock and a 3 inch layer of live sand.
My question is this:
Does anyone have a suggestion on how to transfer everything into a new 125 gallon tank? My main concern is what will happen with the anarobic bacteria at the bottom of the sand bed - will they die off and will they have a detrimental affect on the new tank.
Any suggestions on the topic, as well as suggestions on how to do this switch would be greatly appreciated.
Thank you in advance.

 

[stessman]

are you using equipment form your old tank such as filters lighting exct.? Cause i would think the best and easiest way would be to fill the new tank buy some live sand and put half your live rock in it to cycle it. Then start trasnfering everything over. but if your using some of your old equipment it would be hard to do.