Knowing how much water your tanks hold is very important in aquaponics. Here are the formulas for calculating water volume in a rectangle grow beds.

### How to Calculate the Volume of Water in a Rectangle

I am using a sheet of Firestone 10 X 15 Liner-45mil EPDM. I cut that in half for 2 sheets, and then build rectangle troughs or grow beds out of them. The measurements are approximately 30″ wide x 150″ long x 12″ deep. I default to these numbers to show you the example, but you can enter any numbers you want for your specifics.