Fair point.
"The Lighting Gods of RIU…" love it!
I understand where you're going and, until I went back to the Kind site yesterday, my primary concern was the lack of PPFD maps on the Kind site. To my way of thinking, a vendor's site will put up the information that they believe will do the best to maximize long term profits for the company. If it's on the site, it's there for a reason. Alternatively, if it's not on the site, it's not there for a reason. Kind, historically, did not publish their numbers. Chilled publishes third party efficiency and PPFD data. HLG publishes efficiency reports and has third party PPFD maps for a few of their lights. more manufacturers are posting PPFD maps but the vast majority are in house. Seeing that "everyone" was posting numbers and Kind didn't, I put them in the "Nope" category.
Lo and behold, Kind does publish PPFD charts for their lights! However, when I check their specs, they're still in the Nope category for me. I don't have info on their X Series lights, which they tout at the "commercial" line, but they don't have a compelling argument in their "Home" series, either.
One issue is for growing in a CO2 enhanced environment. I'll impose the "Bugbee standard" when it comes to CO2 - CO2 should be 1200ppm and PPFD should be 1200µmols. "should be" - meaning that's what he recommends in one of his many YT videos (check for a short vid with CO2 in the title but I don't recall the name off the top of my head). None of the Kind X Series lights come even close to a PPFD of 1200µmols so
Looking at the X Series lights, their output is in the Migro array region - they'll get you to the lowest part of the light saturation point but not much further (the range for the LSP is 800-1000µmols). I bring up Migro intentionally, BTW, because Migro is selling below the price of competing lights and one way they can drop their price and still keep their margins is to sell a lower-powered light into a given market.
The PPFD map for the X750 from Kind is shown below. It sells for $995. Lights for a 4' from Mars and Spider are markedly less expensive and generate about 50% more photons than the Kind. And they generate enough light to take advantage of 1200PPM CO2.
View attachment 5339662
What about being able to use the change the spectrum as shown on the Kindsite? Will that make up for the difference in PPFD? I can't see that it will.
"Light color drives plant shape; light quantity drives yield." Nothing controversial there, right? Plants exposed to blue light will be short and compact, while red light "encourages cell expansion". Also we know that there's an almost linear relationship between light levels and crop yield.
OK, those are basic facts about grow lighting. I'll add one more thing - with a fully tunable spectrum, which their commercial light might support but the X series lights don't, you could avoid what I refer to as "the blue photon penalty". Blue photons make a plant grow short and bushy. The low height makes it easier to work with the plants and it encourages branching but
blue photons reduce yield in flower.
The paper "Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids", the Abstract states:
"The lowest fraction of blue photons was 4% from HPS, and increased to 9.8, 10.4, 16, and 20% from LEDs. There was a consistent, linear, 12% decrease in yield in each study as the fraction of blue photons increased from 4 to 20%…Yield was higher at a PPFD of 900 than at 750 μmol m-2 s-1. There was no effect of spectral quality on CBD or THC concentration."
OK, 20W% blue photons dropped yield by 12% so why not get a Kind light so that you can shut off the blue photons flower? Good idea but you can't do that. The X series Kind doesn't have a tuable
The X 750 doesn't have a tunable spectrum, unfortunately. If it did, the yield from a Kind grow might be able to overcome the lack of PPFD. Unfortunately, it's not a tunable spectrum light rather it's "yet another white LED" with a switch that adds some extra red + some far red but there's not way to cut down on the blue photons. The PPFD output is too low to use with CO2 and for any grow that doesn't have an almost perfectly flat canopy, you won't be able to get enough light on a good portion of the grow area to hit the light saturation point. Finally, at 2.55µmol/J their lights are less efficient than the competition. The latter isn't a major point but it does bear mentioning.
All told, I don't see that the Kind X series will generate the yield that a grower will get from lights from other manufacturers that are significantly less expensive and that can be used in a CO2 enhanced environment. I understand that Kind is making controllable spectrum the center piece of their buying proposition but the only data that they offer, the PPFD map, actually works to undercut their argument.
The bottom line - lacking the ability to shut off the blue photons, Kind goes back in the "Nope" category for me.
Really interesting spectrum and excellent PPFD map is the ProGrow 320. It's designed for a 2' x 4' and the fact that their spectrum is a clone of the flower spectrum that Chilled has had for years is quite a fortunate coincidence. Two of those would work quite nicely in a 4' space.