good luck. I built something, not all that different, from wood to hang my pendent. Worked great, but is still a work in process. I found I did not like haveing a lot of stand over the pendent. Have shortened it once, and may do so again.
Meanwhile I have thought of using a single tube and a lot of mending to make something that flows a little more. (come up on a corner, bend outward to mid tank, then bend and cross the tank).
58 gallon oceanic, Kessel 360 tun sun, pressurized co2, eheim pimp #179 - 2217 and diffuser