In the earlier days of LED growing, KNNA was a promoter of photons (efficiency) over spectral distribution and I have always been on board with that. I have seen excellent results (bud quality and yield) from narrow peaky LED spectra like this: deep blue, cool white, 630nm red. I do believe it is ideal to spread the spectrum where possible but not if it requires a significant sacrifice of photons/watt. As you can see from the charts above, the high CRI LEDs suffer a very significant penalty even though their SPD looks very good. I believe we will achieve much better results (than High CRI LED) by simply adding high efficiency deep reds or even just by running 3000K on its own.
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Regarding induction for vegging, I apologize to any indagrow owners if this seems harsh, I am evaluating induction by indagrow's provided data. Induction vs diy LED for vegging, here are my concerns:
-efficiency - not surprisingly, induction's radiometric efficiency is similar to fluorescent tubes. Indagrow claims 60 lumens/watt even on their most efficient lamp and they are short on deep red so spectrum is no excuse for low lumen numbers. That translates to roughly 20%. diy LED can be up to 48.5% (using Cree's minimum figures).
-directionality - induction outputs in 360 degrees versus LED 115 degrees. Despite their claims, Indagrow suffers a very significant reflector penalty. Only a small proportion of its photons are heading in the right direction, and they are not that cooperative when trying to redirect them to the canopy.
-flexibility. with LED I can spread the light where I need it, even in chunks as small as 2W. The height of each heatsink is adjustable if needed.
-spectrum - Induction has high cri but despite that it is still lacking in deep red
-price. Indagrow smallest lamp cost $5/W versus diy LED $2-4/W
-lumen depreciation - Indagrow claims 7% loss in first 2 years VS 1-2% for properly cooled LED.
OK so I am no fan of induction, but I have not tried growing with it or High CRI LED or CMH, so my advice is only valid on paper and I am open to all possibilities.