Why does everyone talk about how many lumens on your plants you need? Lumens is a measure of light as it is perceived by the human eye, which is relatively insensitive to wavelengths around those which plants need. Shouldn't we be talking PARs or something? Or just look at the spectra and see if most of the power is going into those wavelengths needed? I'm not having any luck on finding spectra for any CFL bulbs. Also, color temperature refers to the temperature of a perfect blackbody which would emit light as the same 'hue' as that of the bulb. Are the actual spectra of CFL lights close enough to that of a blackbody for this to actually make sense when deciding what bulbs should be used for vegging vs flowering?
Because bulbs are rated in lumens, not PAR. We can talk about how we should talk about PAR, but we can't actually talk about PAR.
Not really, because we already know which bulbs put out the right color spectra. We may not know the actual PAR, but as long as we use the right bulbs we know that the lumens are in the usable range.