Lights should be 2” from the top of the plant as it grows, so move things up or down as needed. 16 hours ON, and 8 hours OFF - which is JUST as important. They need to rest, as if they were growing in Nature and nighttime rolls around.
Not sure about Pollard’s lights, though. That might be too much heat too close to seedlings at all those ‘lumens’ so you’ll have to research that, but still remember to turn them OFF when you go to bed, or use a timer.
Lights are on when I’m awake but I do have a timer on the way. Johnny’s recommends 3-6” for the lights that they sell and mine are comparable in output to theirs. They’re LED so they don’t put out much of any heat. Just lowered to 4” and I also have a tin foil tent over them to reflect more light onto the plants.