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How do lamps work?

The Swede

New member
I just don't understand at all how lamps work, please help me out.
Let's say you have a room of 15m² (161 Ft²), and you are going have two different choices to grow the largest amount in the room.

A. 10pcs of 200w LED lamps in the room

or

B. 2pcs 1000w LED lamps in the room

You only have 2000W to play with here. Which scenario will result in the highest yield? And why?
 

Porky82

Well-known member
I just don't understand at all how lamps work, please help me out.
Let's say you have a room of 15m² (161 Ft²), and you are going have two different choices to grow the largest amount in the room.

A. 10pcs of 200w LED lamps in the room

or

B. 2pcs 1000w LED lamps in the room

You only have 2000W to play with here. Which scenario will result in the highest yield? And why?
Few more things to consider than just lights!
 

Ca++

Well-known member
Well 1000w of LED, is half a room you say.
If you want to light a long highway evenly, you can't put one big light in the middle. Even coverage, comes from multiple lights, generally at a lesser altitude. You can't get all them little lights, group them up, and stick um up on one huge pole. The effect would be more light than needed, right around the pole. But a distance away, it's dark.
Even if you still run with it, the difference in plant needs might be troubling.

Up to about 650w, some bar lights are physically big enough for a good spread. By 1000w you are looking for a bar light as big as a bed. They don't really make them. Instead, the 1000w is for higher mounting positions. Commercial heights.

A real 1000w LED, is like a 1500w HPS. A light I have never even heard of. It's really too much for a household grow.
 

exoticrobotic

Well-known member
With leds and their narrow angle of light dispersion maybe more lights would be better but then there's more to go wrong and they cost more and i don't grow with leds anyway :D

@Crooked8 would most likely be able to tell you the subtle differences. He's spent a while dialling in larger rooms with leds.
 

PadawanWarrior

Well-known member
With leds and their narrow angle of light dispersion maybe more lights would be better but then there's more to go wrong and they cost more and i don't grow with leds anyway :D

@Crooked8 would most likely be able to tell you the subtle differences. He's spent a while dialling in larger rooms with leds.
True. And efficiency. Less bigger lights would probably be more efficient in terms of power loss, but I still think the spread would make up for it. I prefer more little lights. I have 5 HLG lights in my 3x7 closet. If I was him I'd probably do 4 500 watt lights.
 

Crooked8

Well-known member
Mentor
ICMag Donor
Veteran
I just don't understand at all how lamps work, please help me out.
Let's say you have a room of 15m² (161 Ft²), and you are going have two different choices to grow the largest amount in the room.

A. 10pcs of 200w LED lamps in the room

or

B. 2pcs 1000w LED lamps in the room

You only have 2000W to play with here. Which scenario will result in the highest yield? And why?
Theres a few extra variables here.

Is this 161 sq ft room the total space or total canopy space with ample room to work around it beyond the 161 sq ft?

Also are A and B the only options? Because if so, A for sure, and we would need to evaluate which fixtures youre considering.

Honestly id likely look for something in the middle. Id probably run 6 - 3x6 trays on rolling benches if we only have 161sq ft total. Leaving some room around the canopy to move. Id also shop for fixtures that cover that space well but have the most output. It could be 6 320 w fixtures. It could be 8 250w fixtures. Shopping would be essential, need to find really high output, reliable and efficiency rating over 2.7.

Ultimately you want to spread as many photons across this space as possible. Two 1000w led fixtures would blast unnecessarily high levels of light into a smaller space. 10 200w lamps may more than cover the space without adding as many photons evenly across the space as another setup. We need to find the most efficient lamps that cover this footprint w the given input power.
 

Crooked8

Well-known member
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I've always been quite surprised how high they hang the 1000W hids in commercial greenhouses and wondered how high to hang hids in general.

I suppose I really should get a light meter.
Hanging hids in a commercial setting is difficult. Its not like with leds or even cmh. They shine in a rectangular pattern, part of the distance(5-6ft is typical above canopy) is to get good even coverage, taking advantage of the angular lighting/side lighting aspect of it. As for their pattern its not as simple as lighting directly above each row, the outer most perimeter lights need to be closer to the wall than one might think. Theres a good explanation of this somewhere on gavitas website. But it was not easy to get it right when we built a big one a few years back.

If you are only running a couple lights, lensed single ender 1000w lights thats a different story. You can get closer but yeah a meter tells all, it really helps one know whats truly going on.
 

Rocket Soul

Well-known member
15m2 of cannopy: 2000w of led or hps is not going to light the whole area. If you have an amp limitation you can look into dividing the space in 2 and flip flop; light one side while the other is in dark. This of course with the assumption that you have a separate veg space.
 

DaEarl73

Well-known member
Well 1000w of LED, is half a room you say.
If you want to light a long highway evenly, you can't put one big light in the middle. Even coverage, comes from multiple lights, generally at a lesser altitude. You can't get all them little lights, group them up, and stick um up on one huge pole. The effect would be more light than needed, right around the pole. But a distance away, it's dark.
Even if you still run with it, the difference in plant needs might be troubling.

Up to about 650w, some bar lights are physically big enough for a good spread. By 1000w you are looking for a bar light as big as a bed. They don't really make them. Instead, the 1000w is for higher mounting positions. Commercial heights.

A real 1000w LED, is like a 1500w HPS. A light I have never even heard of. It's really too much for a household grow.
They Build 1000w and more, but i agree with you more small ones to optimice the space. And a led more than 650w makes no sense to me , Because you need to put them higher, like you mentioned! And as usual your response makes absolut sense! Thanks for typing and enlighten the place hahaha
 

ZOnaVerde

Well-known member
Veteran
Greeting!
You asked a very good question!
I'll give you an example from my garden.

1. At the last grow I started with 100W and in the last month of flower I finished with 353W. 100l soil + 25l substrate, pots 11l and the result was slightly over 800g which is right is a little flufy and was not cleaned very well but for me it is ok. Fewer deficiencies and the amount of nutrients was lower. 11° panel inclined inwards

2. At a power of 500-700W the result was almost similar, but the buds much more compact and a little more deficiencies and nutrient consumption. Panel 0°.

My conclusion is that technique and light scattering do more than W use. Conditions were similar. I can't say I got 800g+ 353W because just in the last month they went on this power, right? And we had a consumption of 625kW, so that's 1g+/kW. As in g/W huge amount :joint:
 

Ca++

Well-known member
Greeting!
You asked a very good question!
I'll give you an example from my garden.

1. At the last grow I started with 100W and in the last month of flower I finished with 353W. 100l soil + 25l substrate, pots 11l and the result was slightly over 800g which is right is a little flufy and was not cleaned very well but for me it is ok. Fewer deficiencies and the amount of nutrients was lower. 11° panel inclined inwards

2. At a power of 500-700W the result was almost similar, but the buds much more compact and a little more deficiencies and nutrient consumption. Panel 0°.

My conclusion is that technique and light scattering do more than W use. Conditions were similar. I can't say I got 800g+ 353W because just in the last month they went on this power, right? And we had a consumption of 625kW, so that's 1g+/kW. As in g/W huge amount :joint:
That's interesting. You doubling the power, but not seeing much return from the extra expenditure.
We have seen 350w can take a meter to near 1000umol, from similar grows like @Crooked8 has going on. You don't talk about your space, but I guess in the region of 4x4, or 1.5m2. Maybe you had 750umol that first run. With such a likely breakdown, doubling to 1500umol would be troubling. On a yield vs light graph, we are still in a linear area of increase. On today's graphs. Not on older ones, where gains past about 800umol were few. Today we hear claims 1200umol is hard to work with, without gas. I'm drawn between all these pointers, but do feel 650umol a perfectly good homegrow amount of light. And that light past 800umol isn't giving me the linear returns today's graphs tell us.
 

The Swede

New member
Greeting!
You asked a very good question!
I'll give you an example from my garden.

1. At the last grow I started with 100W and in the last month of flower I finished with 353W. 100l soil + 25l substrate, pots 11l and the result was slightly over 800g which is right is a little flufy and was not cleaned very well but for me it is ok. Fewer deficiencies and the amount of nutrients was lower. 11° panel inclined inwards

2. At a power of 500-700W the result was almost similar, but the buds much more compact and a little more deficiencies and nutrient consumption. Panel 0°.

My conclusion is that technique and light scattering do more than W use. Conditions were similar. I can't say I got 800g+ 353W because just in the last month they went on this power, right? And we had a consumption of 625kW, so that's 1g+/kW. As in g/W huge amount :joint:

Those are very interesting examples, often I hear people just talking about bombing the plants with light/W is the same as a monster harvest. But an even spread seems to be best.

All you guys are smart, makes me feel like a cow
 

ZOnaVerde

Well-known member
Veteran
Without CO2 it is difficult to jump 800 without injuring the plants and in addition at low power the plants develop much faster.

I use CO2 bags (very effective) for each growth from week 3-4 of vegetation, something that allows it to absorb and that allows values of over 800umol up to about 1100 in flower without problems.

Watering is again an important factor l/h, if you use a microdrip system that does not allow soil compaction (it must not dry out) compared to direct watering, it helps their development.


The space is 1.44m² and the maximum power I used was approximately 700W, which affected the plants at a distance of 70cm from the plants.
In general, if the plants develop beautifully at low power in exceptional conditions, there is no point in giving them more light.

More W's do not mean a greater quantity in the final result. The environment and technique bring you 50% of the result, 15-25% microdrip and the compost used and the rest comes from light and nutrients. You can get good results with a maximum of 250w/m² valid for tents.

It is difficult to exceed 1200 umol if it is not in a free room and with a CO² installation, even then inconveniences may occur.
You can't do everything mathematically because yes with ,
It also depends on how you dim, if you go to the maximum in the last month or 2, if you reduce the power in the last weeks of life, sunrise, sunset, ambient, harmony

If you want to have monsters, they are generally made at high temperatures (say above the normal 21 - 27°C) bombarded by many W, something that can affect the quality of the bud, not the quantity.
Good soil, optimal conditions, a led panel developed by a company that innovates in the respective direction.

The next grow will be in September at a maximum power of 400W at 1.44m² and if I don't forget I will share the results with you.

Experience and knowleage hat nothing to do with smart ppl, its just curiosity!
 

Rocket Soul

Well-known member
Spread/even light:
Its almost impossible unless you put some effort into a diy light. Different strategies for different shapes of spaces. Made this for a friend for his 0.80x0.80m :
IMG_20230913_140324_594.jpg
IMG_20230913_140348_847.jpg
IMG_20230913_140419_696.jpg


Separate drivers for dimming the centre and the sides so you can dial in perfect evenness. Also these strips have two channels, warmwhite and coldwhite so you can work them with switches to get either a veg spectrum, full cycle or extreme flower spectrum.
My buddy said he got 350g out of 6 autos with 100w.He had problems dialing in so decided to grow with the minimum light.

Caveat is autos given 2/3rds more light hours and the bud looked fluffy and probably not sellable in a discerning market. For comercial buds have to be properly compact.

If youre getting the same amount from double the watts there is something in your setup that isnt 100%. But yes, doubling watts dont automatically get you more buds. Trick is to know when theyre ready for the light and push them hard.

Microdripp: we run in coco and prefer watering with runoff when the pot is as dry as possible. Dont know how would one check runoff with microdrip? To be able to get the most out of your grow we need to push nutes quite high but still control runoff to see how hot the media is.
 
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