What it is
Too much light right under the lamp. A leaf has a limit on how much light it can use; past that limit, the extra light destroys the chlorophyll and the tissue bleaches. It's not the same as heat (it can happen with a cool room), but heat makes it worse.
How to tell
The highest tips, the ones closest to the lamp, turn pale yellow or white. In flowering, the buds on top get bleached (and lose potency) while the leaves lower down are fine.
What to do
Raise the lamp or turn its power down, and with a par meter keep the tips between 600 and 900 in flowering. What's bleached doesn't recover.
▲ Pros
- If you fix it early it hardly shows at harvest
▼ Cons
- Unfixed it lowers grams and quality
🎮 Practice it in UnderGrow
Only happens indoors, in flowering. Its chance triples above 28 °C. It's fixed by raising the lamp (tap light, in climate › raise the lamp): it no longer burns, but less light reaches the plant (in flowering, up to 5 % fewer harvest grams, depending on the hours with the lamp up). With the par meter it warns you before.
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