get a 1 or 5 gallon water jugs and fill it up keep track and that's how i did it with my 30 gallon
The capacity of the tank is 12.468 gallons (rounded) for each inch the tank is long.
A tank this size can hold a maximum of 3,590.65 US gallons of water.
Hexagon Tank: 44 pentagon gallons
Approximately 201 gallons.
Up to 8,797.1 gallons.
A maximum of 2,019.74 US gallons of water.
Assuming it is a rectangle, 42.077 US gallons
I wonder if it might be 285 gallons!
1056 GALLONS
7615 Gallons
26 gallons for Short Box 34 gallons for Long Box
478.75 gallons of water.