Ok, it’s been years, I’m just starting growing again:
Spider farmer SF4000 (430w LED light w/samsung LEDs), and 2x generic 200w Samsung LED side lights.
Well water at PH 6.5 (measured and adjusted) after adding fertilizer of 6,4,4 Foxfarm Growbig
Foxfarm Ocean soil mix
Fresh air continually going into grow room
18/6 light schedule
Day time is around 76 deg, night drops to 65 or so (it’s very cold were I live so my grow tent is a bit colder than I’d like. This is controlled with a spiderfarmer thermostat/duct fan
The plants are now about 5 weeks old and were doing well but I majorly screwed up. Not thinking and not being used to LED lights, I cranked them all up to%100 (24" from top of canopy). After about 2 weeks the plants showed burn spots on leaves closest to the lights and shade spots were fine looking, followed by the top leaves turning a lighter green color. DAMMIT!
When it first happened I thought maybe I was over fertilizing or maybe the soil was ‘hot’ but did some googling and realized my mistake.
So now where I am at now. I dialed the lights back to %60 instead of %100. According to Spiderfarmer this light will do 1135 PPFD @ 22" from the canopy top. So not owing a PAR meter, I got my phone out, loaded the Android PPFD meter app. Then I calibrated (light at %100) to 1135 @ 22" center of the light. Then I adjusted the light until I achieved around 500-600 PPFD around the entire cop of the canopy which ended up around %60 on the light dial. Hopefully this is ballpark okay. After I calibrated the app, I turned the 2 side lights on and using my ‘calibrated’ phone I adjusted all 3 lights until I was 500-600 at the top of the canopy… HOPEFULLY I am understanding this correctly.
Please review my crap and let me know what/where I may be missing something.