12/12 light cycle

hi can anyone tell me what week to start the 12/12 light cycle at. and i no its 12 hours light but what is the other 12 hours is it darkness or red heat light? thanks for any help

start your 12/12 after you plant matures, when the limbs are not straight across from each other then it is maturing. When you see pre sex showing, behing the nodes, it is mature. You can go with just the limbs though.
12/12 darkness is just that 12 hrs of light and 12 hrs of complete dark, you can put in a green light bulb to help you see in the dark.

your plant should be a minimum of 6-8 weeks old, it grows 2-3 times the size in flowering so how long you let it veg depends on how high you can allow the plant to get

ie: my area is 5' high, taking the light and pot size into consideration, i only have like 3' of space so i let the plants grow for 4-6 weeks or until they are 10" tall, then once they are fully grown the tallest they will be is 2.5' high

the 12/12 is 12 of light and 12 of complete darkness (dont "wake" the plant up during the dark period in flowering)