Bulénath said:Carlos, you need to always keep your numbers adding up to 24 hours. Anything else and they will be prone to hermie.
Our options are 18/6 or 24/0. Which one to use is another highly debated subject.
Some people have mixed results with 20/4. Aside from the first two mentioned, dont try anything else. Stick to the tried and true methods.
Always use 12/12 for flower.
Ventilation is the heart of every grow. The plants depend on having fresh air, as we do. The best idea would be having two fans. One to remove the air, and one to blow on/between the plants and light.
If you have a thermometer, mount it half way to the light, and try to keep it shaded.
The temperature should never pass 85f. Optimal is 70-75f.