I getting ready to build a water tower (see pic below) for the edge of my airport and need you input on the diameter of the tank. I'll be using PVC end caps for the top and bottom of the tanks itself. My choices in diameter are 4.25", 6.25" and 8.25". The legs and cross braces will be something from the Plastruct line with red blinking LEDs appropriately located. Thanks for any help.
