So I have a plant that will have filled up all the space I have to offer in my grow box pretty soon. So I want to know the fastest way to make it bud and how long that will take?
I hate to rain on your parade, but if you have used up all of your grow space for vege then you are probably going to have problems. Your plant is likely to double in size while in bloom/bud. You may have to do some pruning and training to prevent a tangled mess of a plant... but it's well worth the effort. Once you switch to 12/12 light schedule and adjust your nutes your probably looking at about a week or two until buds appear and another 4-8 weeks until they are ready for harvest (usually 45-70 days total for bloom).
Should I keep the same intensity of light on my plant all the way through buding or is less light ok? but will it cause less thc?
If anything add more light during bloom. More light almost always equals a higher yield of better quality bud.
Everything I have seen seems to point towards 12/12 being optimal for budding. I have heard that giving them a full 24-36 hours of darkness right before harvesting will make the plants a little more resinous, but I can't personally verify that.
Putting it on 10 hours of light would prolly make it bud faster, but you'd lose a lot in the yield department. If you're running out of room it might be the only option though...