How close can a HPS get?

So I was wondering for 600 and 1000 watt HPS how close can they get to the top canope of my grow?

The good ole' hand test.

Put your hand at the highest part of your plants.....if your hand can stand it, then your girls should be good too.

For my 1000w I keep it about 18-24 inches away. With the 6 I imagine you could get closer, perhaps 12incehs.

Can I assume you are using an air cooled light???!??

i can get mine about 8 inches away with a 400 watt.

Really depends. I can drop my 600w 4" from my vegetating plants with no problems, however my flowering plants seem to bleach out with the light that close. Typically for flowering it's 12-18" with my 600w and 18-24" with a 1kW

yes I am blowing a fan through the HPS

here is a chart that might helpView attachment 2083593

Depends on your plants and the room environment. You want them as close as you can get them to a certain point. If the temperature permits I've always let 600w bulbs get no closer than 8" and 1000w bulbs no closer than 14".

20in for a 600w air cooled 30 for a 1000.... thats the best distance light does not weaken much and you run no risk of burning ur girls...as said thou every plant and light is a little differnt.

PixiDustr said:

here is a chart that might helpView attachment 2083593

Click to expand...

We did some testing based on that chart and found it to be WAY off. They tell you that a 1000w light at 10" is optimal. In my experience that will fry your plants even if you keep it cool. I think this chart is the best one I have found so far. Lumens and footprint were very similar to the tests we ran with a light meter.

$waGgEr said:

20in for a 600w air cooled 30 for a 1000.... thats the best distance light does not weaken much and you run no risk of burning ur girls...as said thou every plant and light is a little differnt.

Click to expand...

This is definitely incorrect. Light significantly diminishes with every inch and 20" for a 600w and 30 for a 1000w are too far and will cause stretching from vegging plants. If you have an HID light then get the most out of it.

I'm not trying to be a dick Swager cause it's cool you want to help but I have seen you a few places on this forum and your information for the most part is always incorrect and sometimes WAY off. I mean are you just here to fuck around? Not sure but just think about it man... some people have some serious cash into their grow rooms and why just give people bad advice and have them lose that money they invested? There are social networking sites or you can just hang out in Toke n' Talk.

840/2 said:

The good ole' hand test.

Put your hand at the highest part of your plants.....if your hand can stand it, then your girls should be good too.

For my 1000w I keep it about 18-24 inches away. With the 6 I imagine you could get closer, perhaps 12incehs.

Can I assume you are using an air cooled light???!??

Click to expand...

I have a 600W HPS with separate 400CFM ventilation. My girls have gotten all the way to the glass without showing signs of heat stress. I did bend and tie down the few colas that got that high, and I can put my hand right up against the glass. It's warm, but not hot enough to be uncomfortable.
I'd say the more ventilation you put through the HPS, the closer you can get to the tops. Mind you that's with a separate vent path from how you vent your room.