Light hieght

Hi all I am new to indoor growing. A question how far from new seedlings ( just sprouted ) do I keep my light. It is a 600w HPS in a 446 room. I have good ventilation to. thanks

First, you don’t need 600 watts for seedlings. You can use a 45- 50 watt cfl with a 5000 - 6000 K color rating, or you can buy a t5 fluorescent light specifically designed for growing, dirt cheap, and this would be much better for seedlings.

With a 600 watt HPS, it is very easy to know you max close safe distance, only as close as it can get to the back of your hand and still feels comfortable, this is the closest it should be to the canopy of healthy reasonably sized plants.