Plasma lacks the red-far red necessary for flower. So the need for HPS to provide those spectrums in flower is not in debate and in fact recommended by Gavita to add the DE1000 to their 300 watt plasma to achieve full spectrum for flowering. This puts us @ 1300 watts per ~5 x 5. The reason they want you to run the plasma and the DE1000 together is because the added UV-B from plasma, which the HPS alone does not produce, is going to increase trichome production.
To adequately mix the plasma and HPS it's going to require an alternating placement pattern of multiple fixtures as these are both point source technologies. But take away that portion of the equation and hypothesize that a single plasma and DE 1000 will deliver the greatest quality and yield that a grower can ever hope to achieve indoors. Better than any other technology available. If that ends up being the case where does that leave the 1000 watt screw in base HPS lamps? Why would one give up a traditional screw base 1000 watt HPS and invest in a DE HPS of the same wattage unless the DE1000 significantly outperformed a screw base HPS? To achieve these results the DE1000 spectrum would have to be different in that it is pushing farther into the R-FR than the screw base HPS. And if that is the case, there is nothing about a DE1000 HPS lamp that cannot be recreated, should it be warranted, by a screw base HPS lamp that would mimic the exact same spectral distribution as the DE1000 lamp.
Now on to the 1500 watt HPS Ultra Sun. Since we're not considering watts/sq meter efficiencies this is a lamp that would emit ~2200 uMlole at 24" compared to the the DE 1000 that emits ~1500 uMole at 24". If one were to evacuate the heat and raise the 1500 watt lamp by 6" I've actually outproduced the area coverage/intensity of the DE as measured in uMoles by 50%. When dealing in a plasma/hps solution where watts/sq meter is a non factor and one seeks a
higher PPFD value the DE1000 is not going to deliver,
on paper, like the 1500 watt ultra sun lamp would. And these HPS PPFD values have not been adjusted up for the plasma contribution which under a field measurement will add another 20-30% to the total PPFD. I think it's also worthy to note that Sunlight Supply sells both the 1500 watt Ultra Sun advertised at a 206,000 (ahem) lumen output and the DE1000 on their website and they don't reciprocate by providing lumen output on the DE1000.
https://www.sunlightsupply.com/p-15078-digimax-double-ended-lamp.aspx
The average gardener, who buys a limited number of grow lights and lamps over the course of their career, can be influenced by; what the hydroshop salesman tells them is the best way to go, what their grow buddy has been doing 'forever', slick advertising/marketing, or from their own research. If they dig in a little bit and learn what PPF and PPFD means they likely are going make their purchasing decision on which technology has the highest PPF/PPFD values. Yes they will get results but compared to what? Had they chosen to go with an AT or an IG, which approaches plant lighting differently, they would have yielded respectable weights, high quality herb and saved themselves a boat load of money over the years in utility and replacement lamp costs. But they won't know that because the higher PPF/PPFD being advertised won over their purchasing decision.
So I go back to V-C-F as a way of bringing this point back home. See Page 6 @
http://www.inda-gro.com/pdf/MeasuringPlantLight.pdf
If one were to look at the Lumigro 650 it would,
on paper, be considered game over. It would appear we found the best light for plant growth as it wallops every other competing technology with a PPF of 1.8 uMole/Second/Watt. The problem for Lumigrow has been that when trialing a Lumigrow 650 against the competing technologies the plant response has not been positively influenced by the marketing claims of 1.8 uMole/S/W value and will yield according to the combination of spectrum's (or lack thereof) and the intensities which their panel produces.
If manufacturers and wholesalers are going to tout the virtues of their lamps with who has the highest lumen, lumen/watt, lux, uMole, PPF, PPFD values they will continue to perpetuate the myth that these values can somehow define which technology works better when in side by side garden trials the lower PPFD value light can be a much better deal when comparing efficiencies and
actual plant photomorphology between the technologies. Which of course is why these forums (really the only place) showing real garden results with a wide variety of strains, i.e, party cup competitions, is critical in dispelling deeply ingrained notions such as >60 watts/sq foot can somehow spell the successful formula for determining the 'best' light or technology for an indoor garden.
......just a guest though.
