Because of inverse square law... which is largely mitigated by having multiple sources of light in a reflective area, but still plays a part... But this thread isn't really about penetration, it's about DLI.
For what it's worth I agree with @wietefras that in theory 12h x 100W = 24h x 50W. Daily Light Integral is real.
As you say, it is not particularly relevant to flowering photoperiod plants that need 12h darkness... but the important thing to take away is that light energy is cumulative to the...
There's a few variables to consider, but it is common knowledge that 600W HPS is more efficient than 400W... then that extra heat from having 2 less efficient lights is immediately an important factor too.
LEDs only pull as much as the forward voltage they are rated for. Your strips likely each draw around 24v each so what your Kill a watt is telling you is certainly in the right range. You could probably run all of those strips off one of those drivers, although technically you would be slightly...
The Bridgelux EB strips work great if you can find them.
Those look good to me - I like those slimline drivers too! Probably not as efficient as a meanwell, but you could always upgrade driver down the line if you wished. I'd say that looks like a great deal honestly.
I agree with Cobby. Unfortunately these are not gonna be the best for growing because of their efficiency. Are the Bridgelux and Samsung hard strips not available in UK? Otherwise like Cobby says Cutter has flexible strips (if you really need them to be flexible) but I would advise going for the...
Yeah I believe there is a "wakeup" time to be factored in too. I like simulated sunrise for this very reason - why waste power if the plants aren't ready for 1000ppfd yet?!
It all comes down to diminishing returns. Yes you will yield more with more light... up to a point.
If total yield is your priority then squeeze just as much light in there as you can without harming the plants and go at it. If efficiency is your priority then go low power, but focus on good...