it will show if the light is too far, if it is far the plants will be tall, skinny and stretched
if they are growing bushy and with more dense leaves - thats what you would want - it means the light is not too far
cfl are not generating much heat so they can be very close to the plants, young plants are much more fragile and you will probably want the light at least 5-6 inches away from the plants for the first week, then you can keep the lights at about 2-3 inches from the plants