How far should my HID HPS light to be from my canopy?

What are people’s thoughts on this? I have a HID and was wondering how far it should be from my canopy top?

Are you using air cooled hoods? Ideally if you can keep the back of your hand beneath the light and it not get hot that’s kind of the rule of thumb for distance from the canopy .

2 Likes

i fluctuate 600w hps between 20 - 24 inches away usually in flower room… i run barn type refelctor with a 12 in fan pointing at the bulb from several feet away… that is in an open room not a tent…

With my air cooled hoods on my 600 watters I keep them about 18-20 inches from the canopy, sometimes less if I planned poorly and let my girls get too tall, it’s been as close as 12" with no burn using 400 + cfm 6 inch fan to cool the hood.

I’ve got 2 green thumbs but I’m having a hard time growing these seeds. I have a 4’ light strip with grow lights. It’s hanging about a foot & a half above the plants. They’re still leggy. Falling down leggy. How close do I have to be?
I bought fertilizer from u & it says dilute in water but it doesn’t say how much. What’s the mix?