In what way? I think I have a strong understanding household electrical wiring. I installed 2 240V circuits and 3 120V circuits in my basement (in addition to wiring many large grow op. AFAIK, the only differences between them occur at the ends of the wire. The wire itself is the same. Obviously you need the right gauge for the amount of current you're using. Since the power consumption of the light does not change, switching from 120V to 240V will reduce the current ~50%. The advantage of using a 240V circuit is being able to draw more power (Watts) from the same amount of current (Amps) because of the higher potential (Voltage). Power = Voltage x Current. Double the voltage, and you half the current.
You're right that the connections made at both end differ significantly, but how is the wire different? At the breaker, the difference is the white wire is hot (in opposite phase from black). At the outlet, it's just a different type of outlet. So really the only difference is where you connect the white wire at the breaker.
That being said, I wholeheartedly agree with your warning about doing electrical without knowing what you're doing. If you have ANY doubts at all when doing electrical work, STOP! If you already started making changes, do not turn the breaker back on until someone who knows about electrical looks at it. Electrical is not difficult, but it can be extremely dangerous! If you burn your house down because you wired your grow room wrong, I'm pretty sure the insurance company is not going to cover any losses.
Much respect TG. Not trying to argue, just want to understand where you're coming from with this.
