Hey all, I am having some issues with a few strains mostly under my cob leds in flower with yellowing. They looks super healthy up till about 2.5 - 3 weeks in and then they start yellowing badly. The yellowing and dying leaves stop around end of week 5 and what leaves are left green back up nicely. What is it the plants are in more need of during those couple weeks? I have tried upping cal mag and the nutrients in general with little success. The same strains under 630 watt DE CMH do not have this problem at all, and under 1000 watt gavitas the problem is much less, it is still there but not to the extent it is under the cob led fixtures.
I run 1.6-1.9 ec, co2 at ~1100 ppm, ~80-82 canopy temps, ~70 percent humidity with lights on (vpd) and ~50-55 with lights off at ~71 degrees. flood and drain trays, bottom feed in canna coco with canna coco nutrient line + cal mag and mammoth p. flood every 2-3 hours (tried both, same results) when lights on only for 15 minutes each. I have also experimented with jacks 321 and blue planet nutrients farmers pride and elite lines.. same results.
I run 1.6-1.9 ec, co2 at ~1100 ppm, ~80-82 canopy temps, ~70 percent humidity with lights on (vpd) and ~50-55 with lights off at ~71 degrees. flood and drain trays, bottom feed in canna coco with canna coco nutrient line + cal mag and mammoth p. flood every 2-3 hours (tried both, same results) when lights on only for 15 minutes each. I have also experimented with jacks 321 and blue planet nutrients farmers pride and elite lines.. same results.
