Lighting Requirements

[Nightfyre]

How does one determine how many light fixtures they need for their tank? I'm looking at lights for my waterbox 100.3. I'm looking at some viparspectra 165w lights but I don't know if I would need one or two. Is there a super secret formula that I haven't found yet to figure out lights? Lol. So this is what I found on the lights.
One light is ideal for 24”x24” coverage
Max Coverage at 8" height: 30”x24”
Core Coverage at 8" height: 24”x24”

And my tank dimensions are
35.4" × 23.6" × 21.7"

So if I'm understanding this correctly one light is ideal for width of tank but not length. But two would overshoot length by 12". This is where I get confused lol Thanks!

 

[dedragon]

I would run 2 but at lower power if viparspectra is the only option, but I tend to stay away from these standard chinese blackboxes as they are hard to dial in properly without a good apogee par meter.
It would probably be easier to use 2 noopsyche or 2 smatfarms leds than the viparspectra
Amazon product ASIN B08VWRJXS9https://noopsychereeflight.com/products/k7-saltwater-led-reef-coral-lights