Heeey everyone!

I'm trying to build a tank table for a chill out space at a party and for burning man....but the most furniture building I have ever done is putting together some Ikea stuff. I have friends with power drills/tools n things, but I'm kind of not sure if my design is going to work. I was just wonderin if someone could check it out and let me know if something looks horribly wrong. One of the most important things about this is that it has to be relatively easy to move and travel with.
The idea is to make a narrow but long and tall table with a border hanging over....imagine a bar counter...so instead of having legs its kind of a rectangular box. I was thinking something like 70 inch L, 12 inch W, and 36 inch H. I was gonna use 1 inch thick plywood for this part. And then I was going tt use 2 inch thick wood for the border, which is going to hang over the edge 8 inches on all sides. And for the tank part...I was basically going to make a box out of 1/4 thick plywood 68 inch L, 10 inch W, and 10 inch H...cover it with water tight coating. Thats where the water goes.
So the tank would be attached to the border, so I could just set it inside the base. So then when I traveled with it, I would just have the four pieces making up the base, and then the tank and the border would be one piece.
So then I wanted to figure out how much water would be needed, and it turns out that 7000 cubic inches is like 78 gallons of water which is about 650 pounds!!!
Did I calculate that wrong>?
Will plywood even hold that much weight>?
Am I even going in the right direction>?