I think that you have a multi-fold problem with the big plant (s?).
Check the runoff of the soil for pH problems (would be low by the looks of things) and flush to rid it of toxic salt buildup from all the troubleshooting you had already done. Then next time it dries out, transplant it to a larger pot. That pot is too small to support a healthy plant of that size. Go REAL easy on any foliar sprays next time. When in doubt, mix them WEAK!!!
stinkyattic Reviewed by stinkyattic on . Please help me! - Power plant growing indoor - Biobizz all-mix soil with 30% perlite - Ph roughly 6.5 - Tap water with a few drops of vinegar to lower Ph - Plant about 3 months from seed - Baby-bio fertilizer at 5 drops per liter - Fertilized every other watering - 3 x 20w energy saving cfl 3 inches from plant - room temp about 72 degrees 24/7 - relative humidity unknown but it should be low Rating: 5