Wayne Sallee wrote:
That's 4x96=384/125gallons=3.07 watts per gallon. That's only enough
light to grow low light stuff. It would be better to get around 6 or
over in watts per gallon so that you can grow anything.

I never understood the logic behind the straight "watts per gallon" rule
of thumb. It's good for general ballpark, but not much else.

Consider that 1watt of PC lighting has more lumens than 1 watt of
standard flourescent. 1 watt of metal halide light has more lumens than
1 watt of PC lighting.

And of course the lumens per watt vary greatly by bulb model and
manufacturer as well.

Watts by themselves don't give you the full story of how much light will
be produced.