I recently moved a 500 gallon glass aquarium. The glass alone was 1500 pounds. Here is what I did.
*I rented a material lift (small forklift with no engine but a crank and twisted cable). The lift was rated at 750 pounds and I almost broke the lift. Next time I will rent 2 lifts. The lift was used to only move the tank from the cabinet onto the floor.
*A custom 2x4 frame was built for the bottom of the tank. The frame had 6 rope handles (3/4" thick rope) that stuck out from the side. 3 guys on each side could barely lift the tank more than 5 inches.
*We initially put the tank on piano dollys and rolled it. However we had to roll it over rocks and grass in the back yard. To do this we laid down sheets of ply wood and one by one moved the sheets in front of the tank and rolled it along.
*I barrowed a trailer to move the tank as it was 9ft long.
The tank is currently in my garage until I have the money to set it up and stock it. I hope that helps. If you build a 2x4 frame, make sure it is WELL built if the tank is heavy. Is the tank glass?