Light Burn vs Nutrient Burn: How to Tell Them Apart
By The Budometry TeamPublished Updated
Changing your feed when the real problem is your light height wastes a week and often makes things worse. The difference is visible in seconds once you know where to look.
Part of our pillar guide: Cannabis Grow Lights: Sizing, Height and Schedules
Light burn: top-down, tips only
Affects only the tallest tops closest to the fixture. Leaves bleach toward white or pale yellow rather than brown. Edges may curl upward like a taco. Lower canopy looks perfect.
Nutrient burn: bottom-up, browning
Starts as dark green, glossy, clawing leaves, then crispy brown tips that work back along the margins. It appears throughout the plant, often worst on the biggest fan leaves, regardless of height.
The check
Compare a top cola leaf to a mid-canopy leaf at the same age. Damage confined to the top means light. Damage at every level means feed or salt buildup.
Frequently asked questions
- Can I have both at once?
- Yes, and it is common in late flower when growers push both light intensity and bloom nutrients. Fix the light height first because it is a one-minute change.
The full guide on this topic
Cannabis Grow Lights: Sizing, Height and Schedules
How to size an LED to your tent, set hanging height by stage, run 18/6 and 12/12 on a timer, and hit the PPFD and DLI numbers that actually grow flower.