I solved all my issues by backing off my light intensity and/or distance. I also have noticed that the 660 NM spectrum can make or break a soil a grow. Too much, plants burn and/or finish too early. The biggest thing though, move the lights away. Run strains that stack hard and you’ll hit your numbers. Your effective canopy depth will be about 18 inches, so prune everything below that IMO. I also bumped my room temps up to 83-85, as leaf surface temps in LED grows are always lower and can throw your VPD chart off.
LED’s produce full spectrum light, and it’s intense light. You’ll never be able to run them at the strength DWC hydro/flood tables guys do. My theory is that the hydro guys get away with it because they’re blasting plants that are taking in mostly water and only being flooded with food once in a while. If you look at my previous posts, you’ll find that my theory goes more light, more transpiration, more drinking, more nutes. I’ve never seen guys running coco with LED’s slammed on the canopy. If there’s nutes available 24/7, you can’t run as much light because the plant will drink too much and therefore, eat too much. I think a lot of guys running hydro are running too much light and it’s wasteful, in addition to their whole set up being wasteful. That said, you’ll still hit roughly the same numbers if you veg long enough to get plants with a root mass large enough to accommodate lots of light. I’m producing fat sticky colas running my fixtures at around 70% of max power. No problems. Find the balancing point for your strain and fixtures. If your fixture is dimmable, I’d suggest you hit your near peak power early in flower and let the plant “grow into” its preferred PAR measurement. From there, once the stretch is over, you can add more light intensity slowly to increase swell size, watching leaf tips for burn.
Haven’t been back here in a while. Reading this thread shows me how much plant science and behavior I’ve learned since starting lol.
