Here is something very confusing to me. Many LED proponents loudly proclaim the need for 460-470nm red LEDs over the cheaper 630nm LEDs. I understand that this better coincides with the accepted chlorophyll B absorption peak.

So far so good.

LEDs veg very well given appropriate wattage & color.

So far so good.

LEDs do not compare (generally) to HPS flowering as far as yield. (Please - let's not go off in that direction here. Thank you!)

OK, here is the enigma: HPS has a ton of yellow. No LED grow lamps contain yellow. HPS has lots of orange. Some LED lamps contain a little orange. HPS has virtual no Deep Red or Far Red and do very well - yet this is somehow necessary for a good flowering LED light. Even 'inferior' 630nm red is relatively low in HPS.

Any SCIENTIFIC opinions on this major discrepancy?

The only thing I can come up with is that plants rapidly adapt to the core frequency of the light provided which would put in question the whole currently accepted Plant Absorption spectrum.
RackitMan Reviewed by RackitMan on . Importance of 460nm red LEDs? Here is something very confusing to me. Many LED proponents loudly proclaim the need for 460-470nm red LEDs over the cheaper 630nm LEDs. I understand that this better coincides with the accepted chlorophyll B absorption peak. So far so good. LEDs veg very well given appropriate wattage & color. So far so good. LEDs do not compare (generally) to HPS flowering as far as yield. (Please - let's not go off in that direction here. Thank you!) Rating: 5