I've heard 20 - 26 inches for a 400watt HPS and gradually lower it over time, I just recently bought a 400watt MH for vegging, should it be any farther away or closer? How far away should it be to start so I don't burn them? Thanks!

thats way too high.

Look around the site in the FAQ section. I have read that the closest you want to get is 7". A good rule of thumb to use is the "hand" method. If you can hold your hand under it at the distance of your plant for 30 seconds or longer you are fine.

well I looked at the growfaq it says this

"HID Lighting Helpful Tips
.Hanging height: Due to the heat that is emitted from these types of fixtures, you should hang them according to size. Smaller wattage systems (100 and 250) should be hung about 2 to 3 feet from the top of the plants. Medium wattage systems (400 and 600) should be hung around 4 feet from the top of the plants. High wattage systems (1000 and up) should be placed at least 4 to 6 feet from the plant tops."


soooo how is 20-26inches too high when it says 2-3 feet? not tryin to be an ass, just wanna know what is best for my babies!

Heat and burning the plants are your real concern. The plants can handle all the lumens you can throw at them. If your not scorching them, your ok.

Now this is for non-seadlings only. Seedlings need to be handled with more care. For seedlings, drop the light a few inches a night from a few feet until you are as close as your heat output will let you get, not closer than about 7" for a 400W. So I have read.

I just hold my hand at the tops of the plants for a minute and see if it starts to become uncomfortable. If it does, your light is too close.

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