Looks like overfertilizing, and possibly rootbound. Check the roots just before a watering, and see if there's any organic material (potting soil) visible.

Are you adding unsulfered molasses, or any other source of calcium?
Rusty Trichome Reviewed by Rusty Trichome on . Browning Tips - Problems, 5 weeks into flower Hi everyone. I'm getting towards harvest on my first ever grow! I have 3 females out in a greenhouse which I started force flowering on or around the 10th august. The buds are starting to develop well on two of the plants but I am having some major problems with nutrient imbalance, possily lockout? I am feeding them every second watering with a basic tomato feed, approx 5%/5%/5% with some added micronutrients and minerals. The water is approx. pH7 I think. I turned a greening color when Rating: 5