I've read a bunch about the distance a bulb needs to be from the canopy, but am confused. Some information I read says a 600 watt HPS should be anywhere from 10-18 inches from the top of the canopy. Other information says to get it as close as possible without burning the plants. Also, do I count the distance from the top of the plants to the bulb, or from the top of the plants to the bottom of the reflector hood's glass lens? In my setup, that's a four inch diffference, so it could be substantial if distance is really important. Using Lumatek 600W HPS with 600W Digilux HPS bulb.