I'm still not sure what your point is, in all honesty."Directionally accurate approximation"? What in the hell is THAT?
Tells me you think it's all about watts. It isn't, watts is but a small part of the overall growing equation. Actually its light received, not watts that should be the topic of discussion, but you guys always try to paint a black and white picture. A plant starts, grows, and matures as a result of all cultural factors throughout its life cycle, not just one.
Nothing is identical and nothing is constant, that's why "bams/dratt" is such a farce. If it works for you, fine, but you can not honestly use it for forum fodder with any meaningful discussion since there are no constants, and without constants, you can't measure anything with any degree of credibility. A small change in your nute regiment will change the yield which then sends your "directionally accurate approximation" to the shitter. Even lamp quality/integrity varies from lot to lot. Sheesh, are you getting it yet?
If given identical and constant wattage, genetics, lamp, lamp age, distance from plants, temps, nutes, frequency of watering, etc. (you get the drift) and I'm using some parabolic rust bucket of a hood and you're using a fancy smancy horizontal hood with a shiny specular insert designed by a lighting engineer, guess who's gonna realize the most yield?
This is nothing more than "kewl" noob talk that originated from the old ADPC bulletin board (which I posted to) along with the erroneous Lucas formula and alot of other crap that still sticks on the proverbial forum wall.
Speaking of farces, any one of you old timers remember pH's "Yield O Rama"? (now we're going back.....)
If I switch up my nutes and I yield more, keeping everything else constant, then I've increased my grams/watt, and that was a successful change.
And after re-reading your post, I really think it's you who's missing the point - this isn't designed to be Indycar (or is it Nascar? I always get them confused) where everyone uses the identical system (car) and whoever the "best" (whatever that means) grower wins.
This is a way for someone to say, "hmmmm, that guys got the EXACT same setup as me, and I run 10 plants and he runs 40, and his grams/watt is 1.5X mine. Hmmm, maybe I should think about running more plants."
I really can't see where one could disagree with this - is it perfect? No, of course not - as I said before, there's a myriad of other factors to take into account, but as a rule of thumb, this does well.
Is it directionally accurate, i.e. will better growers (or "skilled growers trying to maximize their efficiency", is probably a better way to say it) have higher grams/watt then others, all else equal?
Yes.
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Top for four main branches, tie them down and grow them horizontally just to the edges of the pots, then let them grow vertically from there. My indicas have grown no taller than 25" and sativas 37'' after the final stretch; so far, anyhow. No extra veg time either, because I'm just doing simple tying instead of a major LST job. When looking to save space and ensure light penetration horizontally as well as vertically, topping and tying once has done the job for me. I can have the pots sitting edge-to-edge, and the plants don't block light from each other in the least.
