I've thought about building a spectrometer similar to that one.
Thanks for the knowledge
That does appear to be the spectrum they are claiming. Though I think, and I hope that my red:blue ratio isn't really 70% red / 25% blue. From my simple understanding this ratio may produce undesirable characteristics and a smaller yield.
As for the LUX readings, I figured since it was trying to measure and weigh part of the spectrum that wasn't there the readings should be low and my actual luminous flux should be even higher than metered. If only I could measure mmol without spending $200
. My whole grow cost setup cost less than that haha.
The theory is that blue light above 11% will significantly decrease the yield.
Here is a interesting and super technical master's thesis and labwork that I am using:
https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=5650&context=etd
"At a PPF of 500, increasing blue light from 11 to 28 % significantly decreased dry mass in tomato, cucumber, and pepper, but there was no significant effect on soybean, lettuce and wheat. At a PPF of 200, dry mass significantly decreased only in tomato across the blue light range"
Unfortunately cannabis wasn't a species included in the data but the data shows that red/blue and warm white spectrum produces ideal characteristics.
Disclaimer: I am not a professional scientist or botanist, but I do like to learn how things work and I am learning more all the time. I am not even close to an expert.
Here's some of the data from the paper, the X-axis represents the amount of blue light in the spectrum and the Y-axis represents the dry weight yields. In this data it would seem the RB light is the top performer for the lower intensity data set. Notice the slope of the dashed line is heading down as blue light increases. Tomato yield drops 22% when blue is increased from 12% to 28%, Cucumber 26%, Pepper 15%, and all other species with smaller losses, except for lettuce. I know cannabis has very similar nutrient requirements for tomatoes, but yeah the data from the academic community on cannabis doesn't seem to be available, or the schools are too chicken to even allow the study of it.