m0useanswered grow question 6 months ago It does not work like that. You can try but its not likely to do much.
Giving them less light will mostly stunt their growth unless the intensity is matched. eg 18hr at 40% vs 12hr at 60%.
Something called DLI makes this easy to calculate but it can be tricky. my lights at a hang height of 30" at 40% dim - 16/8 and in flower 30" 60% dim - 11/13 gives me both a DLI of 37.
Max is aorund 40, after that you need extra CO2 to offset the energy.
Good Luck!