Right. This is correct. Except your missing a few key points and your also assuming that more light is always better. Which is a dangerous assumption in a world of 1000w HIDs and overdriven digital ballasts.
First of all - any PAR advantage is going to be negated by the fact that to be properly utilized
Gavita's need to be fairly high above the canopy. If other growers suggest they are using a
Gavita to get a light-print of 4x4, I would suggest that the light isn't properly mounted above the canopy.
Gavita's should be a good 5 - 6 feet above a canopy, in an array with multiple other
gavita's - that are roughtly 6 - 8 feet apart.
It doesn't matter how fucking bright it is once you pull it off to the appropriate height:
https://en.wikipedia.org/wiki/Inverse-square_law
The point is even light distribution without all the supporting bullshit of giant hoods, duct work, cannon fans, etc., for
commercial growers with c2 or i1 or i2 spaces that have 10 - 15ft ceilings and multi-ton A/C. The posters that are focusing on output are missing the entire forest for one fucking bright ass tree.
Oh - and since I'm discussing
Gavita's I will inoculate myself from the fanboys that might seep up out of the wood-work - this is all from
Gavita factory reps at CannaCon2015:
View attachment 567760
A few more things -
No no no no no no.
The instant you start thinking of your plants as "
able to withstand"
you are doing it wrong. You want happy, relaxed plants with happy green waxy leaves. Not
3.5x the light level of the fucking sun for 20 seconds every two minutes or so.
That's basically borderline abusive.
You need to think more biologically and less mechanically - what would build bigger muscles if you were at the gym? 3-reps @ 300 pounds or 30-reps@145?
A single ounce? Off a 3-gallon planter? I'd get 6. If you want a bunch of lil plants 3-gallons is lots of rootzone volume. I grow in 2.5 gallon hempy buckets and I routinely hit 4 - 6oz's out of an overhead lit trellis. 1000w HPS's turned down to 60% at the ballast.
Maybe 1-gallon planters 6 - 8 inches apart. Veg for a week after clone then flip. I might shoot for 48-plants total - 12 per 4x4 square of your tent...
Cooling isn't going to be your issue here - your issue is appropriate light-print. 1x1k
Gavita - however you choose to employ it - will
absolutely not out-yield 4x600w HPS's over that same space unless you purposefully fucked up your plant layout.
I get how you've built these lights up in your mind.
It reminds me a bit of the way car stereo guys used to flip over JLAudio13w7's. Like the
Gavita's, they
are really neat pieces of gear - but almost never appropriate for the rest of the install.
http://www.jlaudio.com/car-audio-subwoofer-drivers-discontinued-w7