Aquarium Update

Here is my original set up. Two ten gallon tanks on a stand that DH bulit in the early 90's to house our DD's pet hamsters. We originally had one ten gallon tank then inherited the other from DD#1. She condensed a 29 gallon tank into a ten. Bad idea. In hindsight I should have encouraged her to bring over the 29 and set it up (this was last Nov.) but anyway.......DH bought the 55 gallon tank at a yard sale last summer and it just needed a little washing, especially after sitting in our garage for 11 months since he bought it. He bought it with a stand but the stand was, primitive at best, and not "house worthy". Last week we found a stand at WM and now were in business.
With the old set up moved to the side (read previous post for that story), the new tank is set up and last night was filled with water. I added a capful of Prime to the water and I intend to take some rocks from tank one and add to the new tank to help speed up the eco system. If anyone has any tips on speeding up the eco system, please feel free to share! I'm wondering if putting a goldfish in it will help speed things up but then what would I do with him when the tank is ready?? Like I said, any tips would be greatly appreciated. I want to transfer the fish before we go on vacation to reduce the risk of tank problems while we're away.