Too much light? Upward-curving leaves and foxtailing

[Petinha88]

One thing that makes me think it may not be the light is I think you said youve been dimming them but the lower leafs taco too which unusual. Also that your temps are perfectly fine.

I said it might be the light because i think the plant, when saturated with light, curls its new leaves upward to reduce light absorption. The upper leaves are a bit crispy too.

However, I forgot to mention something important. It hasn't even been two weeks since I moved the grow to a much cooler location and under the air conditioning. At one point, it reached 31°C.

 

[medidedicated]

Thats ok temps still I was rockin 91F this past summer. The switch might of called for dialing in the new location. I get slightly different grown in my new veg tent. Let alone if I flowered down there.

 

[Delps8]

I said it might be the light because i think the plant, when saturated with light, curls its new leaves upward to reduce light absorption. The upper leaves are a bit crispy too.

However, I forgot to mention something important. It hasn't even been two weeks since I moved the grow to a much cooler location and under the air conditioning. At one point, it reached 31°C.

Cannabis will grow well at 31°. The optimal temperature for vegetative growth is 30°C/85°F.

The plants are reacting to too much light.

A mature cannabis plant will thrive in 800-1000µmol, the difference being some strains are able to use more light than others.

If a grow is not able to tolerate that much light, it's probably because there's something wrong in the grow environment. I've seen two grows, on another cannabis site, where the plants weren't able to tolerate > 500µmol and, in both cases, poor watering practices had turned the soil hygrophobic.