Total hours of light for early stage seedlings

I like them to sprout in light, but it doesn't matter. With seedlings you can save watts getting light nice and close and figuring out power through trial and error.. at normal hanging distances, maybe 1/3rd power to start. The growth you observe is the best way to adjust from there. Too stretchy and it needs more... too tight and it needs less... there's a happy zone to find. local variables impact the amount of photosynthesis per day - more relevant to mature vege plants. So, any suggestions likely need some adjustment. Allow the growth pattern to verify your choices. Growth is the product of all the variables. Stick to whatever schedule you plan to use for your autoflowers - consistency is best. Don't change it thinking it helps - it doesn't. The only reason you'd want to use 24/0 is with an incredibly under-powered light. In any common sense context you shold be able to provide 'max' dli relative to your local variables with a properly sized light over 18 hours or less. read up on dli (daily light integral). thinking of light as 'hours of operation' is insufficient. DLI also makes any comparison apples to apples regardless of size of garden or hours of operation. Also, 35 dli will result in an equivalent g/sq ft yield regardless of hours of operation, all other factors remaining the same. Good research backs that up. It's not anecdote.