Quote Originally Posted by Monty View Post
awesome so i have 2 custom almost 70 gallon hex tanks with radiant heat panels sitting in my moms garage
L x W x H is accurate for most rectangular tanks, but for a hexagonal tank you will have to calculate for the volume of a hexagonal prism (a shape with a hexagonal top and bottom, and six rectangular sides). It's sort of complex, but it's basically 3 x a x s x h = Ah, where a = apothem length, s = side, h = height. If you can give some dimensions I can figure it out for you.

edit:: apothem is the distance from the center of the base to the middle of one of the side panels (NOT the corner), basically like the radius of a circle. You can measure across the top of the tank from the center of one flat side to the opposite one, and divide by 2 to find it.