COCO COIR What causes this?

[fishinthesea333]

Hello all 👋🏼👋🏼👋🏼
Got this starting to happen. Can someone help diagnose the problem? It seems to be spreading!!! Many thanks for any help!!!

[golfnrl]

Hello fishinthesea333 you'll need to provide details about your grow. Is that a single leaf on different plants? Is that problem everywhere? Spreading? How? To other plants or just all over the same plant? Is it at the lower portion of your plant? Is it in the middle? At the top? Detail your feed schedule, ph, rh, lights, pots, etc and someone will weigh in. Until then take a look at the plant problem chart that Nebula developed. It's over on the GWE web site.

[Rwise]

Did you get water on them with the lights on?

[fishinthesea333]

Started lower-mid area of one plant, spread to top and now spreading to nearby plants. Outdoor grow, weather has been very hot and wet. Nutrients given every second day. Have been extremely healthy until this.

[3Berries]

What's the underside of the leaf look like?