Establishing bacteria will have little to do with saving the water and more with allowing bacteria time to spread over surface areas, as noted above.
I have always been amused by the concept of saving water from tanks. Better to hang on to some established filter media, plants from an established tank, driftwood, anything with good surface area. All of that is infinitely easier for getting bacteria into a new tank.
Last edited by wheatiesl337; 10-25-2012 at 05:44 PM.