The 30 inch mark is right where you should be. 30-38 inches is the accepted standard for a 600w LED. You have to remember that those LEDs are putting out a lot of light that we cant see. The plants can. Remember what i said aboit newer growers always wanting to do more, to so SOMETHING with the plants? Just makes sure youre giving them what they want and need and not what you "feel" they should be getting. This is exactly why so many new growers over water their new plants to death. Everything looks good bud, just let them do their thang.