Here are the results:
Tank Volume: 347 gallons
Water displaced by Sand and rock: 22 gallons (Assumes sand weighted dry and rock weighted wet)
Net water volume: 325 gallons
Surface area: 1751 sq inches
Content weight (water sand and rock): 2,172 pounds
Approximate tank weight: 520 pounds. Excludes top bracing weight. If braced add 22 pounds (See below). Cast acrylic density assumed at 0.043 pounds per cu. inch.
Total weight: Approx 2,620 (unbraced) to 2,642 (braced) pounds. I would recommend check floor support capacity if tank will be located on a floor supported by hoists or beams (other than basement floor).
Excludes water content and weight of the rest of the system (Stand, sump, refugium, frag tank, peripheral equipment and piping)
These measurement shall only approximate the final ones. rock and sand bulk density changes considerably as well as acrylic density.
No weight for top bracing is considered. Assuming bracing equivalent to 25% of the bottom area and 1 inch thick the weight added by the bracing will be about 22 pounds.