Its 330 gallons totalI don't know what wood you're using, but here's a calculator. Six 2x4's (Douglas Fir) should support around 3,816 lbs. dead load.
https://courses.cit.cornell.edu/arch264/calculators/example7.1/index.html
The math of the load is roughly 8.5 - 9.5 pounds per gallon assuming decor. How many total gallons do you think you have?