The tank was moved into place this past Monday (4/4). Originally, I had laid 1/2" styrofoam beneath the tank, but in four seperate sheets (as that was the only way I could get enough foam from Home Depot). Unfortunately, each sheet of foam compress a little differently from the others, so I had to come up with another solution. I have family in commercial waterproofing (which coincidentally uses lots of foam and other compressable materials), so I consulted with my dad and he suggested that I use a sheet of 1/4" polyester. That was placed under the tank last night, and it works likes a charm!
Here is how the tank looked Monday evening (4/4) sitting on the foam with a 100 gallons of water or so compressing the foam.