I just did it with 13.75.
https://www.autoflower.org/threads/autocob-grow-with-big-sm0-and-mephisto.57154/
Daily light integral. 12 vs 24 your basically doubling the watts per square foot as the light hours are doubled. Now my photos take as much as I can give.
https://www.autoflower.org/threads/autocob-grow-with-big-sm0-and-mephisto.57154/
Daily light integral. 12 vs 24 your basically doubling the watts per square foot as the light hours are doubled. Now my photos take as much as I can give.