We have very different points of perspective crimble, and your arguments are fine. But they're only a reproduction of the popular discourse surrounding led lights. I'm wide awake and its morning so I shall deconstruct.
About the "ballasts" - you are correct, that an led consumer does not have to purchase his own power supply, primarily because allowing the user access to the wiring isnt a fun contingency to deal with. But leds do not simply use the power coming out of the wall. There are two different types of current, alternating, and direct, leds are direct... and power over lines is alternating.
In a hid set up, they make you buy the ballast. Why? cause they have a short lifetime. They make you buy bulbs... why? short lifetime. the user is responsible for replacing these items... Well, leds are rated to mantain (commonly) 70% of thier luminous flux over 50,000 hours. a very long time. The leds will pretty much last forever, but the power supplies... will not last as long. So, to sell a unit with an internal supply, is cheating the consumer, cause its not gonna last much longer than 5 years maybe, but once it dies the whole unit is dead, when the important component, the leds, are still fine and dandy. SO, like the hids, you should be willing to think about an led light as seperate components, not a sealed body with one explicite function running magically out of pins in the wall.
I can't argue for your consumer awareness. I'll bet, and i hesitate, but do you use apple products? I really would like to know...
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As for the other bit, well ok first wattage equivelency considering yield. NOWHERE NOT HERE NOT ANYWHERE HAS ANYONE EVER SHOWN ANY KIND OF EQUIVELENCY. not for what we do. ever. I havn't even seen a 1 gram per watt grow using leds, which is standard yeild for a 600 watt hps.
You are right about lumens being a useless measurement for the photosynthetically active spectrums, PAR. Lumens are for humans. PAR is for plants, unfortunately, lumens is the industry standard for "effeciency" in light sources and isn't likely to change, as led manufactures don't give a shit about one particualr market like that to have the engineers go run the tests and stuff.
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When you talk about color... that is all advertising hype. you read that on product web pages. not on here. not real people talking, but someone trying to sell you something, and you beleive it. Do you use apple products?
85% of a hid is largely useless, but its still not, its just less effeciently used by the plant.
It is nm range that is important, but then why do hps grow so damn good?
because they are fucking intense. 20000 lumens is a lot of light. a little fucking sun.
what matters is, on the biochemical level,
is a photon and the energy that it is being captured by a chloroplast. it does, and it doesnt have to give a fuck about wavelenght, the process is just more effecient in certain ranges.
What is more important, is bombarding the plant with as much light as possible. getting as much reception of photons as possible. FLOWER, POWER.
again,
they're trying to sell you lower watts, and claiming the color to be a substitute for power, heat and size, which is not the correct way to approach increasing yield.
you're going to be dissapointed operating under your current assumptions. you wanna put down 20watts per square foot, be my guest. That simply isn't enough PHOTOMETRIC FLUX, umols of photons, to produce heavy fruits. It is not enough energy.
nobody can refute this go find other led grows everyone realizes that they spent 400 dollars for only 90 watts of power and that they got ripped.
Compare your light in dollars per watts first. that is the only metric you can really trust as a consumer. everything else is variables that you know nothing about.
i apologize for being so forcefull. fighting popular discourse is a passion of mine.
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My plants look healthly and bushy !! In flower stage right now with some nice hairs beginning to appear all over