If you’re in a room with few to no lights, there’s no reason to illuminate your plants on the sun’s schedule. You can set up a timer so your plant lights are on anywhere from 12 to 18 hours per day. There are a lot of theories on what light/dark cycle works best for each plant. Once again, experimentation is key. However, for starters, try 16 hours of light to 8 hours of dark since that’s what they would receive outside during the height of summer.