Yeah youre right. But all im stating is my real world observations of: the bulbs are deffinatly brighter brand new than they are after 9-10months use (3 grows) and that the super lumen setting is a good tool to use on the last grow with the particular bulb.
And just to touch on the 5% i agree i made a mistake thinking it correlates that way, but could 5% light loss not equal 5% less weight because the light is the means of energy for plants, provided that everything else in the grow is identical 5% less light mean the plants recieve 5% less energy? I get 1.4gpw if i use 1000w i get 1400g if i use 5% less light i would get 1330g at 950w?
Edit: just realizing that 5% light loss does not mean 5% watt loss
also found this pic
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