OK bro.....here's the straight dope, no BS.
The seed needs to crack open in the dark, which means it needs to be under dirt, coco, vermiculite, in a rapid rooter plug....somewhere where it will not be exposed to light. Amongst botanists and professionals there is no debate....due to gravitropism and phototropism, not to mention the fact that roots aren't supposed to be above ground....seeds are supposed to be PLANTED when they sprout, if you want healthy plants.
There needs to be bright light to greet them the moment they break ground.....really bright light. I put a 40,000 Lumen 8 bulb T5 an inch over the emerging seedlings.
Then there is the issue of humidity:
Please don't trap humidity with your seedlings! Clones are what needs humidity, because they don't have roots. A seedling has plenty of roots by the time you see it. The humidity accomplishes nothing but stunting root growth, stressing the plant and very possibly starting a fungus problem, like damping off, or powdery mildew.
Stress on seedlings favors males! Here's a recipe for males:
1.)Any kind of stress. Sprout the seeds in a paper towel, then drop and injure them as you try to put the emerging radicle in dirt.
2.)High humidity...put a dome over your babies and they turn into big strong boys
3.)Low light. Let 'em stretch, that stresses 'em out and you'll most likely get boys
If you want females:
Minimize all aspects of stress during the first 3 days of the seedlings life
1.)Put the seed in some medium where it is dark, even with bright light shining on it. Dirt or rooter plugs work well, rockwool too. Make sure the medium is moist, not drenched. It needs to stay moist, so you might need to spray it or use a small dropper if the medium dries out. If using soil or a plug, one initial watering outa do the job.
2.)Keep the temp at a constant 72 once you see the seedling emerge. You will see faster sprouting if the temp is warmer, but lower temps favor females!
3.)Keep the humidity at around 60%.
4.)Make sure there is a source of nitrogen for the emerging seedling. Fox Farms Ocean Forest soil, amended with perlite will have enough nitrogen. Higher nitrogen favors females.
5.)High light levels, especially in the blue spectrum favors females. Place your CFL's, or T5's an inch---no more than 3 inches----above the emerging seedling. They LOVE this.
HID's work well too, but you don't want to overheat (stress) the seedlings, so I prefer T5's or CFL's in the blue (veg) spectrum.
People will do what they want and I respect anyone who is germinating Cannabis seeds, regardless of the method they use. The above method is a no BS, reliable scientific way of germinating seeds. It works.