# Does size matter w/ light wattage

• None

#### Amatfumusviriditas

Been gnawing on this for awhile, not sure if thought process is valid or what leads me to consider it but,
considering PPFD,DLI and similar measures equal, can, for the oversimplified sake of argument, the same quality final product be produced with a 400w as with a 1000w, the primary difference being yield? OR does the initial increased intensity of the source lead to increased density, terp production, etc?
The math seems to tell me they should be equal quality different yield, but I can’t imagine growing a 1x1 space with 40w??
Perhaps the math shows greater ratio of usable light lost with lower initial light intensity, resulting in decreased maximum potential, meaning what’s left of the light energy just can’t get the plant to optimum? I know I mixed measurements, not trying to compare apples to oranges, I hope I made clear the concept I’m wrestling with and relative feedback is appreciated.

#### Ddebrazza

More watts= Larger Yield

Quality would more come down to the genetics of the strain and how you care for your plants

#### lvstealth

Supporter
i use 4 lights in a 4x4 tent. it works just as well, maybe better than running with one light.

#### growsince79

Been gnawing on this for awhile, not sure if thought process is valid or what leads me to consider it but,
considering PPFD,DLI and similar measures equal, can, for the oversimplified sake of argument, the same quality final product be produced with a 400w as with a 1000w, the primary difference being yield? OR does the initial increased intensity of the source lead to increased density, terp production, etc?
The math seems to tell me they should be equal quality different yield, but I can’t imagine growing a 1x1 space with 40w??
Perhaps the math shows greater ratio of usable light lost with lower initial light intensity, resulting in decreased maximum potential, meaning what’s left of the light energy just can’t get the plant to optimum? I know I mixed measurements, not trying to compare apples to oranges, I hope I made clear the concept I’m wrestling with and relative feedback is appreciated.
150w hps can make buds just as dense and potent as a 1000w. The new 100w leds can replace a 150w hps. Rock solid, just need the right genetics.

#### growsince79

i use 4 lights in a 4x4 tent. it works just as well, maybe better than running with one light.
i use 3 100w in a 2x4 works great for different size/age plants..

#### Amatfumusviriditas

150w hps can make buds just as dense and potent as a 1000w. The new 100w leds can replace a 150w hps. Rock solid, just need the right genetics.
Thanks for the confirmation, I appreciate the feedback from all as I have only used lower wattage lights (350) to this point and have yet to hit my mark quality wise. I make improvements and get closer with each grow but can’t quite seem to get there, wanted to confirm that the potential was there with what I’m using. I suspect now my challenge to be better ventilation and “ finding a keeper”. Which leads to my next question-
How much difference between a keeper and non keeper when pheno hunting and how rare are keepers? ( obviously depends on breeder, genetic pool, etc, but in general?) I’m only running maybe 2-6 per run so wondering about my odds. In the past most everything is pretty neutral regardless of strain, send or clone-looks good, potency acceptable but little to no odor (even during grow and late flower) or flavor. Been at it off and on since 2013, a cycle or two the last couple years. Currently HLG, jacks and soil.

#### growsince79

Totally depends on genetics and what you're looking for. Lets say you have 6 females and one is noticeably stickier and tastes better than the other 5. But out of the other 5, 1 is almost just as good as the first prospective keeper but gets ripe two weeks sooner and still yields more. Now which one is the keeper? If the genetics are solid they should all be great. But yeah, there's always one that's just a bit better.

#### Amatfumusviriditas

Totally depends on genetics and what you're looking for. Lets say you have 6 females and one is noticeably stickier and tastes better than the other 5. But out of the other 5, 1 is almost just as good as the first prospective keeper but gets ripe two weeks sooner and still yields more. Now which one is the keeper? If the genetics are solid they should all be great. But yeah, there's always one that's just a bit better.
Appreciate your time, thanks. Sounds like I just have more personal improvements in technique to make and dial things in more. I know my dry/cure process needs fine tuning as well but you can’t lose what isn’t there, even at full flower I’ve gotten by without needing a carbon filter, except last run. Back to the drawing board.

#### growsince79

Appreciate your time, thanks. Sounds like I just have more personal improvements in technique to make and dial things in more. I know my dry/cure process needs fine tuning as well but you can’t lose what isn’t there, even at full flower I’ve gotten by without needing a carbon filter, except last run. Back to the drawing board.
IMHO is mostly genetic. I've had plants from good seeds growing under horrible conditions that made stickier, stinkier better smoke than perfectly grown buds from mediocre strains.

#### Frankster

##### Seshat; Goddess of Wisdom, Knowledge, and writing.
Supporter
Been gnawing on this for awhile, not sure if thought process is valid or what leads me to consider it but,
considering PPFD,DLI and similar measures equal, can, for the oversimplified sake of argument, the same quality final product be produced with a 400w as with a 1000w, the primary difference being yield? OR does the initial increased intensity of the source lead to increased density, terp production, etc?
The math seems to tell me they should be equal quality different yield, but I can’t imagine growing a 1x1 space with 40w??
Perhaps the math shows greater ratio of usable light lost with lower initial light intensity, resulting in decreased maximum potential, meaning what’s left of the light energy just can’t get the plant to optimum? I know I mixed measurements, not trying to compare apples to oranges, I hope I made clear the concept I’m wrestling with and relative feedback is appreciated.
It boils down to spectrum ratio, and especially how close the photon's are to the actual leaf... As a light distance increases, the photon intensity decreases...

In a nutshell, this is my views on the subject:
The most efficient lights in HPS is going to probably be 400's spread out... But the most efficient lighting (besides our sun) is LED lighting, (LM301 being the front runner right now) combined with Osram 660's + IR + T5 UVA+B IMO...

It also produces far more complexity in the flowers.
Disclaimer: HPS are some fine lights, that produce fantastic results.
lighting is a controversial subject here at the farm. You ask 10 people, you'll probably get 7-10 different answers.
But I've probably spent >\$10k on lighting in the past decade, so I think my views are somewhat impartial, and based upon real world experience.
That said, I've got lots of small grows (different lights) under my belt, not some of the massive ones you see here.

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#### growsince79

It boils down to spectrum ratio, and especially how close the photon's are to the actual leaf... As a light distance increases, the photon intensity decreases...

In a nutshell, this is my views on the subject:
The most efficient lights in HPS is going to probably be 400's spread out... But the most efficient lighting (besides our sun) is LED lighting, (LM301 being the front runner right now) combined with Osram 660's + IR + T5 UVA+B IMO...

It also produces far more complexity in the flowers.
Thats a cool picture but it's not exactly right when it comes to leds. It works for a single point of light real good. At 2' the light is 1/4 as strong as it is at 1'. With led, when you raise the light from 1 to 2 feet, the only point of light that's twice as far away is the diode in the very center. The rest of the diodes aren't twice as far away-they are something less. So when you raise the light from 1' to 2', the lux is not 1/4 as much as it was at 1'-like it would be from an single point of light.

#### lvstealth

Supporter
love it @growsince79, solid explanation.

also consider the makeup of the light, it is not a light, it is hundreds of little lights. so when you show source light it is actually a ton of those cones, all slightly offset from the last. so you have light overlap which adds light, but not like you think... so, it is far more complex than we like to think. not to mention, the spacing and location of the different frequencies they use!

#### growsince79

love it @growsince79, solid explanation.

also consider the makeup of the light, it is not a light, it is hundreds of little lights. so when you show source light it is actually a ton of those cones, all slightly offset from the last. so you have light overlap which adds light, but not like you think... so, it is far more complex than we like to think. not to mention, the spacing and location of the different frequencies they use!
I saw studies comparing diffused light to direct light. Diffused light definitely helps, but plants given both diffused and direct light did the best. I think partly cloudy days was the best. Indoors HPS and led mix very well.

#### Frego

Can I ask a question real quick

ive a 450watt all spectrum it gives out heat

will a 250watt give out the same amount of heat

Same brand same make

#### growsince79

Can I ask a question real quick

ive a 450watt all spectrum it gives out heat

will a 250watt give out the same amount of heat

Same brand same make
Just a wild guess, but I'd say more power makes more heat.

#### Amatfumusviriditas

Can I ask a question real quick

ive a 450watt all spectrum it gives out heat

will a 250watt give out the same amount of heat

Same brand same make
I would venture to guess depends upon light source as different types have different efficiency producing light vs heat, but short answer is yes, more watts more heat, but a noticable difference is the real issue. There are calculators to determine cooling needs vs light source, that could give you an idea of the difference. https://horticulturelightinggroup.com/blogs/calculators

#### MIGrampaUSA

i use 3 100w in a 2x4 works great for different size/age plants..
While there is some truth to "more light = better bud," that's not linear. Your lighting needs are determined more by the space you're trying to fill. I use dimmers on all my lights and I target my lighting needs at 40watts per foot square. This is slightly more than is actually needed to produce good flower, but with the dimmer I have control and can tailor the amount of light to the plant with it. Why is this important? Because just as much as you need a full balanced spectrum of light, you can also provide too much light on the plant too. Too much light intensity will burn your girls.

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