FrayedKnott
New member
I'm stacking two bare 600w HPS with a 14" fan blowing the heat up. How for should the plants be away from the stacked lights to keep from burning?
Thanks!
Thanks!
Plant Distance from Bare Bulb?
- Thread starter FrayedKnott
- Start date
Legendary
Legendary
This legendary site will explain all:
http://www.angelfire.com/cantina/fourtwenty/yor/yor.htm
To summarize, you will want to get absolutely no closer than 1 foot from a 600w bulb (if your heat is even under control that close), and closer than 1.5 feet should be regarded as "the DANGer zone".
If you are trying to maximize the usable light hitting the canopy and don't care much about what is below it, shoot for just under 1.5 and the canopy will be getting all she can use, and you will therefore be getting the most possible canopy that is saturated with usable light.
It all depends on what you are shooting for, though.
Legendary
This legendary site will explain all:
http://www.angelfire.com/cantina/fourtwenty/yor/yor.htm
To summarize, you will want to get absolutely no closer than 1 foot from a 600w bulb (if your heat is even under control that close), and closer than 1.5 feet should be regarded as "the DANGer zone".
If you are trying to maximize the usable light hitting the canopy and don't care much about what is below it, shoot for just under 1.5 and the canopy will be getting all she can use, and you will therefore be getting the most possible canopy that is saturated with usable light.
It all depends on what you are shooting for, though.
FistedSister
Active member
greetings from a bare bulb jedi
greetings from a bare bulb jedi
homie because of variables such as ambient temp, circulation and strain ... i'd push them close to the bulb as possible using the back of your hand as a guide to find a comfy spot. try nudging the plants closer, till you see sign of stress, then back off a little. of course the plants are gonna grow straight towards that bulb. so training, staking and so forth will be needed.
careful in there playa
greetings from a bare bulb jedi
homie because of variables such as ambient temp, circulation and strain ... i'd push them close to the bulb as possible using the back of your hand as a guide to find a comfy spot. try nudging the plants closer, till you see sign of stress, then back off a little. of course the plants are gonna grow straight towards that bulb. so training, staking and so forth will be needed.
careful in there playa
Ravi Singh
Member
Yeah, what he said - I use a vertical cooltube but have four 600s stacked on top of each other - I took lotsa readings with my lux meter and 18" is the sweet spot - I'd imagine your readings would be similar because even though you're bare-bulbed (slightly more lumens), the fact that I have four stacked should just about even that out.
Lemme know if you want the readings and I can dig them up.
I
IE2KS_KUSH
Re: Plant Distance from Bare Bulb?
^
I dunno...i can get to about 8 inches with my vertical bare 400, maybe even closer than that I think 12 inches would be a bit much?
^
I dunno...i can get to about 8 inches with my vertical bare 400, maybe even closer than that I think 12 inches would be a bit much?
I
IE2KS_KUSH
Re: Plant Distance from Bare Bulb?
Hell when I start using a fan under each bulb I bet I can get even closer, why would that wasteful
Hell when I start using a fan under each bulb I bet I can get even closer, why would that wasteful
Ravi Singh
Member
The closer you get to the bulb, the smaller the diameter of your radius, reducing your canopy size and eliminating a large benefit of having vertically hung bulbs.
FistedSister
Active member
7 plants around a 600
7 plants around a 600
about this far for example
the wookie
7 plants around a 600
about this far for example
the wookie
I
IE2KS_KUSH
Re: Plant Distance from Bare Bulb?
Sure that makes sense, plant numbers and size factor in, assuming the size and numbers allow what would be bad about having them as close as possible, even if its < 12 inches.
Sure that makes sense, plant numbers and size factor in, assuming the size and numbers allow what would be bad about having them as close as possible, even if its < 12 inches.
diminishing returns, the buds will only develop so good the closer to the bulb, <12 is about that on a 600... if you dont have plant numbers you have veg time, bigger the canopy the better the yeild as long as its properly lit...
so to answer more astutely less yield gpw wise.
who.d
edit: having a 400 10 inches from plants is like having them 17 inches from a 1k... so 10-12 actually is prolly spot on for a 400
Ravi Singh
Member
That chart (have never understood why people use it) is so incorrect it's not even funny.
The readings are nowhere near reality - it's quite ludicrous if you really look at the numbers.
The readings are nowhere near reality - it's quite ludicrous if you really look at the numbers.
I
IE2KS_KUSH
Re: Plant Distance from Bare Bulb?
Diminishing return that's what I was wondering thanks..
Diminishing return that's what I was wondering thanks..
Start them 3' from the lamp. They will stretch toward the lamp. They can finish within 6" of the lamp... Think about How the plant grows. Real bushy on the bottom, with a few long colas sticking out the top. The colas aren't going to block that much light... However yes, the closer you get an object to the light, the less light can pass it and hit what's behind it...
Multiple lamps stacksed are even better than single lamps... by increasing the light intensity farther from the lamps... In this pic the plants are only 2' from the lamps. I'm missing out on some serious sq footage...
Multiple lamps stacksed are even better than single lamps... by increasing the light intensity farther from the lamps... In this pic the plants are only 2' from the lamps. I'm missing out on some serious sq footage...
Ravi Singh
Member
If anyone is interested in what causes this, it's the difference between line source light (multiple stacked bulbs) and point source light (one bulb, obviously).
Line source decreases at a rate of I/D, where as point source decreases at a rate of I/(D^2).
Whereas we can never fully replicate true line source light (for our purposes, think of the sun), the more bulbs you stack the closer you can get to it.
EDIT: HydroId, do I know you from another website? Running 70 plants around a couple of 400HPS?
a lot of it depends on strain. some strains love lots of blasted light at them and some bleach and burn easy. same goes with air circulation and how close your fans are. some strains wind-burn if too close.
12-24 inches from a 600 is pretty standard and will give you decent nugs.
i would try to move, rotate and train the plants throughout the grow. after-all the sun does not remain at the same location all the time...
i have a seen a horizontal garden with aircooled hoods which had the lights positioned 36" from the canopy. it was 2 - 1000w HPS with CO2, ebb & gro hydro and AC... 5.5 lbs dry. Most people would say that 3 feet is too far (especially for an aircooled hood), but this guy produced great medicine and his system & strain worked from that distance.
12-24 inches from a 600 is pretty standard and will give you decent nugs.
i would try to move, rotate and train the plants throughout the grow. after-all the sun does not remain at the same location all the time...
i have a seen a horizontal garden with aircooled hoods which had the lights positioned 36" from the canopy. it was 2 - 1000w HPS with CO2, ebb & gro hydro and AC... 5.5 lbs dry. Most people would say that 3 feet is too far (especially for an aircooled hood), but this guy produced great medicine and his system & strain worked from that distance.
