Is there so such thing as TOO much light?

datshieeet

datshieeet

Active Member
Like most newbies I started out with a grow box and some CFLs. As my knowledge grows, I keep upgrading my equipment.

I now have a 2.5 x 2.5 x 5'5" grow tent, and I am looking to maximize my yeilds in this tent. Since the amount of light you have directly effects your yeilds, is it safe to assume more is ALWAYS better?

Or should you limit the amount of light within a certain space? Is there a wattage to area ratio that should be followed?

for example:

Will a 1000 watt HPS in that small space just burn everything to a crisp?

Is a 120 watt LED too small to get a decent yeild?

I am considering purchasing a mars hydro II 900(420 real watts), will that be too powerful for that small area? Should I step it down a notch? or is more ALWAYS better?
 
Bbcchance

Bbcchance

Well-Known Member
I've light bleached plants with 600w hps+6oow of mars, younger plants don't need that much, but when they grew to flowering size they loved it, but before you go out and buy that big mars light, go to the led and other lighting sections under General growing and see what others have done with them, you may decide to go with a different lighting idea, not saying you will, but several growers end up replacing the 3w diode leds with cob lighting far before the mars have earned their money back....that said to answer your question, no as long as you can keep it cool you can use it without frying plants if you leave enough space under the light
 
HydoDan

HydoDan

Well-Known Member
You only have 6 square ft x 50 watts= 300 watts.. A 400 watt hps would be more than sufficient.. But I would recommend looking at Timder led grow light kits. Easy to put together.. quality components...
 
Chef420

Chef420

Well-Known Member
I have experience growing in a tent that size. Whatever direction you go in, a big consideration is the heat. I bought a 2x4x5 kit and it came with a 600w hps/mh and WING reflector. I recognized the problem almost immediately and had to buy a cool tube.
 
datshieeet

datshieeet

Active Member
Chef420 said:
I have experience growing in a tent that size. Whatever direction you go in, a big consideration is the heat. I bought a 2x4x5 kit and it came with a 600w hps/mh and WING reflector. I recognized the problem almost immediately and had to buy a cool tube.
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Thats why I'm gonna stick with LEDs because they give off much less heat, I will also be adding a carbon filter and fan that will vent directly outside through ducting in the ceiling. right now my tent is running at 86 degrees (30 celcius) which I know is a little too warm.
 
datshieeet

datshieeet

Active Member
Michiganmeds1982

Michiganmeds1982

Well-Known Member
datshieeet said:
Thats why I'm gonna stick with LEDs because they give off much less heat, I will also be adding a carbon filter and fan that will vent directly outside through ducting in the ceiling. right now my tent is running at 86 degrees (30 celcius) which I know is a little too warm.
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I'm 86 I'm my room most of the day, but my room is 6feet by10 feet 9 foot ceiling
 
Afgan King

Afgan King

Well-Known Member
Uberknot

Uberknot

Well-Known Member
With a small tent and not much height....which I have..... 150 watts actual is a lot of light with cobs. I can use up to 250 watts with my light, but never would it would be too much lux/lumens/heat...make sure you have a dimmer.

You lose plant growing height area with pot height and distance to light. If you do not have a light meter I would get one.

Think more about the amount of light and heat at the surface of the plants.

Here are some basic guides I found about testing lux and what it should be at for different stages. It's not the end all be all , but it helps figuring out the amount of light you approx would need. Different strains can take more light than others.

Quick Guide - Lux Levels for Optimal Cannabis Growth

Life Stage MaximumGood Minimum
Vegetative 70,000 lux 40,000 lux 15,000 lux
Flowering 85,000 lux 60,000 lux 35,000 lux

< 15,000 lux - sparse or "stretchy" growth - plant isn't getting enough light
15,000 - 50,000 lux - good amount of light for healthy vegetative growth
45,000 - 65,000 lux - optimal amount of light for cannabis plants in the flowering (budding) stage
70,000 - 85,000 lux - a lot of light, some strains do okay at this light level, but some plants lose their top leaves early under this light intensity, especially plants that are not resistant to heat/light (like many indicas)
> 85,000 lux - at this light intensity, you've hit the plant's "saturation point" which means your plant can't use all the light. ( bleaching can happen. )

more info

Light Requirements of “High Energy” Plants

Amount of luxPlant Growth
1000 – 5000 lux Min. necessary for life
10000 – 15000 lux Min. necessary for consistent but sparse growth
20000 – 25000 lux Min. necessary for robust growth
25000 – 30000 lux Max. Efficiency for Sub Tropical varieties
25000 – 50000 lux Max. Efficiency for Equatorial varieties
Plants need 25000-50000 lux too grow fast.
 
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SPLFreak808

SPLFreak808

Well-Known Member
200W cob led ,315 lec or 400w hps all work great for that amount of space.

1000w in 6sq.ft will fry almost everything and give you much more trouble then its worth.
 
slow_grow

slow_grow

Well-Known Member
My space is slightly bigger and I ended up going with a timber 300W Cree CXB3590 kit. Gathered the parts for the frame at lowes and made it in a few hours. I did a review on it actually, here is the link: https://www.rollitup.org/t/newbie-experience-with-timber-grow-lights-diy.918881/

Dan was great and I've heard great things about the folks at Cutter too. This was after going through 2 sets of LED panels.
 

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twalte

twalte

Well-Known Member
Afgan King said:
So I'm pullin two a light with 40w per sq ft? 12x8 room 4k watts. And that's not even mid range?
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Afgan King said:
Or 41.6w same shit lol damn that sucks
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Your still putting out more than 5800 lumens per square foot ...more than anyone like myself running a 5x5 tent with 1000 watts HID (5600 lumens or 40W per square foot) or a 4x4 tent at 600 Watts (5625 lumens or 38 W per sq. ft), and you see some beautiful grows from both of those setups. I think it's easy to get hung up on the "optimum" number when many have shown that "midrange" numbers provide excellent results.
 
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Skunk Baxter

Skunk Baxter

Well-Known Member
twalte said:
Your still putting out more than 5800 lumens per square foot ...more than anyone like myself running a 5x5 tent with 1000 watts HID (5600 lumens or 40W per square foot) or a 4x4 tent at 600 Watts (5625 lumens or 38 W per sq. ft), and you see some beautiful grows from both of those setups. I think it's easy to get hung up on the "optimum" number when many have shown that "midrange" numbers provide excellent results.
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Definitely. One of my lights is 38-40 watts per square foot, and the other is 47. The one that gets 38-40 watts is more than good enough; I'd be happy spreading the other one out to cover more square footage too, if I could. But I can't, because it's a tent. I consider a lot of that light wasted watts; i'd rather have a slightly larger footprint and spread the light out a bit.
 
mauricem00

mauricem00

Well-Known Member
datshieeet said:
Like most newbies I started out with a grow box and some CFLs. As my knowledge grows, I keep upgrading my equipment.

I now have a 2.5 x 2.5 x 5'5" grow tent, and I am looking to maximize my yeilds in this tent. Since the amount of light you have directly effects your yeilds, is it safe to assume more is ALWAYS better?

Or should you limit the amount of light within a certain space? Is there a wattage to area ratio that should be followed?

for example:

Will a 1000 watt HPS in that small space just burn everything to a crisp?

Is a 120 watt LED too small to get a decent yeild?

I am considering purchasing a mars hydro II 900(420 real watts), will that be too powerful for that small area? Should I step it down a notch? or is more ALWAYS better?
Click to expand...
yes even with fluorescent (T5s) if you get the light too close plant growth will slow down. leds are so focused that they can actually kill leaves if placed too close. with HIDs heat in your grow room will likely become an issue when you get too much light as well
 
mauricem00

mauricem00

Well-Known Member
datshieeet said:
Thats why I'm gonna stick with LEDs because they give off much less heat, I will also be adding a carbon filter and fan that will vent directly outside through ducting in the ceiling. right now my tent is running at 86 degrees (30 celcius) which I know is a little too warm.
Click to expand...
not all LEDs give of less heat. the cheap ones sold on E bay produce about as much heat as CFLs. high end LEDs may produce a little less heat than HIDs or T5s in the 400 watt range in a tent that small 300 watts of actual power should work fine but with only 5 1/2 feet of height to work with you may not be able to get cobs far enough away from your plants to get even light distribution. a 315 lec may be a better option in that size of tent
 
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