metal halide light distance 600w

Oddly enough im finding very little on this when googling. Most people are only concerned with light distance in flower. but I find that easy to figure out. My question is how far should the light be from plants during veg? some people say 3 ft, others say 2 ft, and some whackjobs put their light at the ceiling. Anyone have anything a little more concrete?

As a first time grower I haven't found a lot of answers on this either. I have often been told as close as you can while controlling heat and prevent burn to the plant. However, I was recently suggested to raise my lights as my "need to stretch." The recommendation I received was between 24-30" above the canopy of the plants.

Granted its my first grow, but this was the recommendation I had received. Interested to see what others post!

1) You didnt say how big ur MH light is.
2) You dont say how the bulb is mounted.

Light height is dependent on heat... you can get 2' away in an air cooled hood w/ good canopy breeze, on 600-1000w... (pushing it on the 1k tho)

Take away that canopy height fan..... (wall mounted oscillating, its well worth the $40) and that moves to like 3-5'...... MH gets warm....

More info = more accurate help....

Yodaweed said:

View attachment 3653799

Click to expand...

thats a flowering chart. A chart that isn't as helpful as it may sound. it says that any distance on 600 watt from 8 inches - 29 inches is optimal. Im not too experienced, but 29 inches is not what I would call optimal.

Flagg420 said:

1) You didnt say how big ur MH light is.
2) You dont say how the bulb is mounted.

Light height is dependent on heat... you can get 2' away in an air cooled hood w/ good canopy breeze, on 600-1000w... (pushing it on the 1k tho)

Take away that canopy height fan..... (wall mounted oscillating, its well worth the $40) and that moves to like 3-5'...... MH gets warm....

More info = more accurate help....

Click to expand...

Heat isn't usually an issue. because veg plants can handle higher temps than flower. it's 600 watts, and its in an open reflector Adjust-a-wing, although I don't worry too much about heat, i can't get as close as an air cooled because the open reflector passes more heat, uva, and uvb than an air cooled. Although I could potentially bring it within 10 inches if I wanted to without worrying about heat, they would definitely get light stressed.

Hey can anybody tell me if this is marijuana or not? I'm not a grower, just found it in my front yard!

LizaBRry99 said:

Hey can anybody tell me if this is marijuana or not? I'm not a grower, just found it in my front yard!

Click to expand...

Sure looks like it to me.

LizaBRry99 said:

Hey can anybody tell me if this is marijuana or not? I'm not a grower, just found it in my front yard!

Click to expand...

pinch a leaf off with ur nails n give her a smell

I run a 600 MH and my height is determined by a couple things. I am illuminating a certain space. That and the heat have me maintaining things between 18-22". Open-wing reflector.

If you're in a tent, all the way at the top. If you're in an open space. 2-3.5' depending on plant size and how they respond to the light. That being said I've had plants grow into the glass on the hoods for my 600s and 1000s and if your temps are in check you can be pretty close. But further is better, to a point.


Sent from my iPhone using Tapatalk

LizaBRry99 said:

Hey can anybody tell me if this is marijuana or not? I'm not a grower, just found it in my front yard!

Click to expand...

You lucky person, I am off to check my yard

kmog33 said:

If you're in a tent, all the way at the top. If you're in an open space. 2-3.5' depending on plant size and how they respond to the light. That being said I've had plants grow into the glass on the hoods for my 600s and 1000s and if your temps are in check you can be pretty close. But further is better, to a point.


Sent from my iPhone using Tapatalk

Click to expand...

Dude,
3.5'?!?!? See the chart you liked above. Why bother with a 1000 watter if you are going to waste it like that.

Secondly...granted, I have never grown in a tent, but your straight to the top advice seems too general.

And your "further is better" advice is news to me and the chart maker.

12 inches.

DANfour20 said:

12 inches.

Click to expand...

Nawww. We are talking non-aircooled 600w MH Unit (also just like mine) and they would burn at 12". Your coverage would not be enough for a 3x3 either, at a foot.

bravedave said:

Dude,
3.5'?!?!? See the chart you liked above. Why bother with a 1000 watter if you are going to waste it like that.

Secondly...granted, I have never grown in a tent, but your straight to the top advice seems too general.

And your "further is better" advice is news to me and the chart maker.

Click to expand...

Yeah, If you understood how light works in a closed space you would understand the correctness of my "general"(more specific actually as there is only one of "the top" in a tent. You obviously don't understand light distribution and footprint or the way that light is absorbed by plants. Any experienced grower on here will tell you closer is not usually better. It's all the new growers that don't understand how to utilize their light correctly that try to grow with his lights intentionally 6-12" from their plants.

In a tent situation all of the light is reflected and absorbed, so there is no waste of light when it's higher. The only thing you're doing by keeping your lights insanely close in a tent is chancing bleaching and burning of the Top calyx of your nugs or heat stress. Ever notice how the buds directly underneath your tops are almost always greaser than the actual tops because you have scorched the terps by the insane ir/leaf temps at your canopy.

As I said, in an open space what I was saying about higher being better is only up to a certain point as you are actually losing the light when it doesn't initially hit your canopy.

Growers that grow by charts don't generally understand what they're doing or why they're doing it. IMO.

kmog33 said:

Yeah, If you understood how light works in a closed space you would understand the correctness of my "general"(more specific actually as there is only one of "the top" in a tent. You obviously don't understand light distribution and footprint or the way that light is absorbed by plants. Any experienced grower on here will tell you closer is not usually better. It's all the new growers that don't understand how to utilize their light correctly that try to grow with his lights intentionally 6-12" from their plants.

In a tent situation all of the light is reflected and absorbed, so there is no waste of light when it's higher. The only thing you're doing by keeping your lights insanely close in a tent is chancing bleaching and burning of the Top calyx of your nugs or heat stress. Ever notice how the buds directly underneath your tops are almost always greaser than the actual tops because you have scorched the terps by the insane ir/leaf temps at your canopy.

As I said, in an open space what I was saying about higher being better is only up to a certain point as you are actually losing the light when it doesn't initially hit your canopy.

Growers that grow by charts don't generally understand what they're doing or why they're doing it. IMO.

Click to expand...

while I appreciate any advice that comes through, I think that you underestimate how much PAR is actually lost through distance. The visible light itself doesn't really matter (do you know how many of these novices are giving a shit about lumens? it's sickening) even without glass every few inches decreases the PAR given off by the light significantly. to have your light more than 3 feet away just seems like a waste of electricity to me.

papa canna said:

while I appreciate any advice that comes through, I think that you underestimate how much PAR is actually lost through distance. The visible light itself doesn't really matter (do you know how many of these novices are giving a shit about lumens? it's sickening) even without glass every few inches decreases the PAR given off by the light significantly. to have your light more than 3 feet away just seems like a waste of electricity to me.

Click to expand...

That just is not the way it works in a closed situation lol. Light is absorbed and therefore any usable light will be absorbed(under the circumstance that the light is contained, i.e. Tent) and is not wasted. So the total par/ppfd of your panel matter more than the intensity at any one point. I can promise,if you're someone who has their system dialed and grows with your hids 12" from your plants, that if you raise your light 1-2', you will have better results, more even coverage , and a wider footprint.

You cannot "waste electricity" if that electricity is going to light that is definitely used by the plant. The only waste of electricity is past the point of light saturation. Which, none of us home growers are doing it would be insanely expensive.

Satvied and I had a convo about it on a thread very similar to this one that was posted about a week ago. Called something like, "professional facilities light distances" or some shit like that.

Run your light as close as you can with out burning the plants.

I have my 600mh in veg about a foot and a bit off using a cooltube.

kmog33 said:

That just is not the way it works in a closed situation lol. Light is absorbed and therefore any usable light will be absorbed(under the circumstance that the light is contained, i.e. Tent) and is not wasted. So the total par/ppfd of your panel matter more than the intensity at any one point. I can promise,if you're someone who has their system dialed and grows with your hids 12" from your plants, that if you raise your light 1-2', you will have better results, more even coverage , and a wider footprint.

You cannot "waste electricity" if that electricity is going to light that is definitely used by the plant. The only waste of electricity is past the point of light saturation. Which, none of us home growers are doing it would be insanely expensive.

Satvied and I had a convo about it on a thread very similar to this one that was posted about a week ago. Called something like, "professional facilities light distances" or some shit like that.

Click to expand...

well if it means anything, I am not in a tent. This is actually a spare bedroom, but I did the best I could to cover the walls with an expensive highly reflective film.

I've been running a 600w open bulb for a few years now and 20" is the sweet spot for me in my 4x4 tent. I've never burned my plants at that distance and I get great yields too.