Yeah, a 200 gallon tank will weight about 300 pounds, see if you can get a few more people to help you. Largest tank I had moved by hand was 240 and that was a real struggle, took me and 3 people from my gym (which was a strongman gym at the time) to move it, it weighed close to 400 pounds and each of us could lift that weight up and carry it with no problem, but the shape of the tank and the fact there is nothing to really hold onto made it very difficult.
