Help choosing an LED replacement for 1000HPS?

I would use all 3500k before mixing 3000k and 4000k. Too many variables with proper height and reflector or lenses to get a proper mix at the canopy and below. The only mix I would consider would be adding some deep red or UV to a white to add something that may be lacking in the white.

Darth Vapour said:

but i want the sun in my grow room not just one spectrum of it

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We all do.

mc130p said:

Here you go:

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Do want.

captainmorgan said:

I would use all 3500k before mixing 3000k and 4000k. Too many variables with proper height and reflector or lenses to get a proper mix at the canopy and below. The only mix I would consider would be adding some deep red or UV to a white to add something that may be lacking in the white.

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Right, someone did an analysis combining white temps and the spectral chart was almost identical to the middle temp in a single cob. Might as well decide what temp you want and go with it. My personal experience with 3000K has been very positive all around so I'm not sure how big a difference there is when it comes down to it, 3000, 3500, 4000. We might be hemming and hawing the concept to death when in practice it matter little.

If cob tech catches on in the horticulture market, we may start seeing horticulture specific Phosphor blends.

Has anybody ran those plug and play solar pannels that go back into the grid via 120w wall socket? I seen mixed reviews about safty and legal concerns but depending on your position from the equator I heard the pannels themselves work great, especialy when wind can blow fully around then to keep them cool on those bright days

AquariusPanta said:

I've seen a lot of sprectal distribution charts for Bridgelux and Cree COBS, but not very many for other lighting solutions. I know you've been around this technology for quite some time now, Supra; where do you think Vero and Cree COBS place amongst the other lighting options when it comes to sprectral distribution?

As far as PPFD goes, how many photons should we, as growers, be aiming towards throughout seedling/vegetation and flowering stages? In other words, what do you believe to be the ideal?

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The ideal PPFD depends on stage and quality of light:

With HPS I tell people 1000 mmol / square meter
With full spectrum I tell people 700-800 mmol / square meter

Why the difference? Well, the HPS dominant green and yellow wavelengths (~500~600nm) of light travel further but are far less useful for photosynthesis. These wavelengths are great for our eyes demonstrated below but not ideal for plants. Each wavelength of light has it's own photosynthesis factor for each type of plant. Plants have optimal photosynthesis <500nm and >600nm, but that being said it's a misnomer that the green wavelengths cannot be used for photosynthesis and do not wake up plants (they do). Thus, you need slightly less mmol of full spectrum lighting to create the same amount of photosynthesis as an HPS.



So what excites me about this industry is there is still so much to learn and so much research left to do around how wavelengths of light effect different strains and how different ratios of wavelengths are consumed.