Auto OG Kush

This is indeed the general idea and you are correct in your assumption my friend. Cannabis plants want three things from their light. High concentrations of PPFD in the range of 1500 - 2000 PPFD, Relatively stable heat from the light source around 70 - 80 degrees Fahrenheit and light in the correct spectrum for the stage of growing that they are in which means more blue and white light during vegetation with a small amount of red spectrum mixed in and then more red spectrum with some blue and white spectrum mixed in for flowering. Depending on the light source that you choose to use you would want to keep your light as close as 12 inches from the plants if you are working with low powered and low temperature LED's to up to three feet from the plants if the light source is incredibly powerful such as HPS and HID's. Measuring the amount of light using a PPFD meter and measuring the temperature of the top of your growth canopy can give you a good indication of when you should be moving your light upwards or even possibly lowering your light closer to your plants. I hope I've helped my friend. Cheers.