Lumens are for humans…. the plants can utilize the whole PAR/ePAR spectrum for max growth. I usually push my plants a bit, so I run ~1543 umol/s for 66.6 DLI in 12/12. I dunno about your phones, but uncalibrated neither of my phones would read anything close to that, so I bought a Uni-T UT383BT lux meter. Its still a lux meter, so I can’t get a proper profile for/reading on the spider farmer SE7000 yet; I use ‘natural daylight’ in the PPFD Meter app to read that high.[ the next nearest profile ‘3500k +10% 660nm’ doesn’t go above 1350 umol/s reading, even point blank]. That being said its factory calibrated to 5% deviation and will handle up to 200k lux, so it’s at least not sitting at max the whole time like my phone’s sensor does. I hear the photone app can read somewhat accurately on iphones.
