LED vs HPS

kylepc91

Well-Known Member
Ok so I drew you in to explain some things and ask a few questions.

1. It was explained to me that more wattage in your light source, either it be LED or HPS, the more penetration your light source has. The comparison was explained to me like this: for every 100 watts of HPS, you need 70-80 watts of LED to equal the same penetration. IE 800watts of LED = 1000watts of HPS.
As a reminder, when I say "you need 70-80 watts of LED to equal the same" I mean you need 70-80 watts of actual draw power. So when someone boldly claims they have an 800w LED, ask them how much power it draws. Most of the time LEDs aren't run at full power because if they were, they would burn out relatively quickly. For example I have 2 100x3w LED panels (300 watts) but they only draw 187 watts of power, which means they run at about 62% power, drastically increasing the life on the bulbs, but lowering penetration.
Assuming this is correct, and taking the higher number just to be safe:
HPS to LED conversion (HPS wattage x 0.8 = LED equivalent)
LED to HPS conversion (LED wattage / 0.8 = HPS equivalent)

That being said, is penetration what determines the size of the lower buds? Is that the only thing it determines? If so, using methods like the Scrog method would mean I would need less wattage for penetration?

2. Some people state that an HID bulb only has 17 usable lumens per watt, while an LED fixture usually has around 43 per watt.


Does this mean that most of a HID light is wasted?
Does this mean that the 6000-7500 lumens/ft2 rule isn't that reliable?

3. With all that being said I arrive to even an even bigger question.

What is that maximum amount of lumens usable by 1 plant? Is there one?

4. Assuming that there is a maximum amount of lumens that a plant can use, there has to be a point where wattage only matters for penetration. But also assuming that penetration is only for more light distribution for your lower buds, methods like the scrog method would make it obsolete to have a high wattage bulb, because once you have reached that maximum amount of lumens, the only thing that matters is how well your light is spread.

Also, are lumens stackable? Say that I have 1 400 watt HPS bulb - 45,000 lumens roughly, then I add another bulb in there for another 45,000, totaling 90,000 lumens. Well that doesn't make much sense to me that they would stack. My logic being this; Bus A traveling at 45 miles per hour stops and lets half of its passengers onto Bus B, which is heading to the same destination at 45 miles per hour. 45mph + 45mph from 2 different vehicles doesn't = 90 mph, as they are both only going 45 mph. Passengers A will arrive to their destination roughly at the same time Passengers B arrive. Except more gas and space on the road was wasted for no different results, when both group of passengers could of taken 1 bus, and been more efficient. The only way this would of been logical is if there was not enough room on Bus A (light spread).

Unless you need 2 bulbs just to spread the light out or higher wattage for penetration ( if you aren't using a training method) I don't see the sense in it. Wouldn't it make more sense to just have multiple, lower wattage bulbs for light spread? Seeing as both bulbs are producing the same amount of lumens at the same rate, the availability of light increases but the size and space of the grow area did not, and the rate at which plants photosynthesize did not increase, as they are only going to use what they can use.

Thank you if anyone read all of this. Hopefully someone can correct me and explain this to me a little better.
 

richinweed

Active Member
lumans stack...U can clearly see this in overlap areas in the light footprint...also i have used both hps and led...evan a 150 watt sunmaster hps will blow away a blackstar 240....130 actual watts.....there is a benifit learned for me here...im new to micro grows...i thought i would try led for the known benefits...they work awsome in veg...but lacked in the bud production which i was accustomed to, with the adition of equal amounts of hps. i was achiving traditional growth for less watts and heat...led's rock , but sadly are best as a companion light....the two togeather seem to make small grows viable .otherwise it wouldnt be worth it to me to continue in this endeavor....these are real world observations ..lacking any speculation or other agenda.
 

kylepc91

Well-Known Member
lumans stack...U can clearly see this in overlap areas in the light footprint...also i have used both hps and led...evan a 150 watt sunmaster hps will blow away a blackstar 240....130 actual watts.....there is a benifit learned for me here...im new to micro grows...i thought i would try led for the known benefits...they work awsome in veg...but lacked in the bud production which i was accustomed to, with the adition of equal amounts of hps. i was achiving traditional growth for less watts and heat...led's rock , but sadly are best as a companion light....the two togeather seem to make small grows viable .otherwise it wouldnt be worth it to me to continue in this endeavor....these are real world observations ..lacking any speculation or other agenda.
Ok, if they do stack, there has to be a maximum point. You can only get so much out of a plant. That is what I'm trying to understand.
 

FranJan

Well-Known Member
OK, stand back I'm gonna take a crack at this. Oh and Hello Kyle.

1. Throw out the whole first paragraph, because you can't compare apples and oranges, i.e. one can argue that 900 or 1000 or 1100 watts = 1000 HID watts, thus leaving the shorter second paragraph wherein you have actually answered your own questions in that paragraph. Also see those X-lenses that some companies are pushing.
2. Yes, Not for HID probably. And some people are crazy.
3. Easy. The minimum and maximum lumen used by a plant is zero or as someone on the internet put it "Lumen is the level of colors that human eyes are most sensitive to, such as yellow. These colors are not the most beneficial to plants. It is the colors in the light that affect our eyes the least that help the plants the most. Because of this, effectiveness of lights for a plant should never be based on lumens." I'm a big fan of that last part there when it comes to LED.
4. Because of 3 I don't have to answer 4, but I will say it ain't that simple, it's physics if you will. Also weird interactions can happen when certain wavelengths are present, something like the Emerson effect can occur and in reality people don't know too much about how plants really use light all that well. And right now, when it comes to LED you can use low wattage or not and training or not or spend the big money to get coverage and energy,..... or not.

OK I'm not tryin to be a wise-ass or comedian really. I think I gave it a good go there actually :). But my question to you is, what are you trying to figure out? There may be a simpler way to find an answer to all those questions in your post. There's so many variables in LEDs that it's really hard to compare them to HID. Sometimes LEDs aren't the answer for some situations, that's what I'm really saying. Peace Kyle!
 

richinweed

Active Member
Ok, if they do stack, there has to be a maximum point. You can only get so much out of a plant. That is what I'm trying to understand.
..thats a good point..maby someone can answere...but from real world experience..the more k hps the bigger the nugs ..light saturation may not exist in the grow room setting.....im not sure what ground out door level lumun count is to compare to 4k hps....this bieng around my traditional grow, so evan with 4 khps i dont think i was near saturation.....the point that i a was trying to convey and im wondering if others have noticed this..you need significantly less hps when subbed with led...(in the bud spectrum)...the other thing that never make sence is par..led users always tote par as the way to measure led lights...when you see the data it would appear led light is perfect and productive...but in the real world the inneficient brute force of the hid lights always wins...jmho...based on the real world ...
 

FranJan

Well-Known Member
you need significantly less hps when subbed with led
Best of both worlds, right? Brute force of the HPS and then slamming the plants with the LEDs specific spectrums. I wish I could run a CMH/HPS with my panels, but where I'm at it ain't gonna happen. Someday though.
 

kylepc91

Well-Known Member
What I'm asking is, other than going higher in wattage for more penetration and light spread, what is the point in going higher in watts? A plant is only going to use so much of a light bulb, there has to be a certain wattage or spectrum or whatever you want to call it that will allow it to grow optimally, not compromising yield and saving yourself energy. Obviously the more plants you have the more light you would need. I guess you can get a 1000w bulb, a bunch of plants, and just light up those motherfuckers without worrying about it, but I guess I'm not programmed to do it that way. I just wanted to know how much light exactly each plant uses so I can supply my plants with it and train them accordingly. Sorry if I'm finding it hard to explain myself, I just worked a 12 hour shift and sat through a 3 hour lecture hall. Tired as hell. Thanks for all the helpful info thus far.
 

Gastanker

Well-Known Member
depends on too many variables. closest decent answer you should get for that questions is a 600w lamp covers a 3x3-4x4 canopy and a 1kW lamp covers a 4x4-5x5 canopy.
 

kylepc91

Well-Known Member
depends on too many variables. closest decent answer you should get for that questions is a 600w lamp covers a 3x3-4x4 canopy and a 1kW lamp covers a 4x4-5x5 canopy.
Going over and over it in my head, now understanding why there is too many variables but still left with my same question. Damn, exhaustion has me wanting to roll a fat one and mindlessly go stare at my LED television. I wonder if I stuck my LED television in my grow room and left it on Jersey Shore if my buds would resembles the "blow out". Anyone have any scientific explanation to this hypothesis.
 

curly604

Well-Known Member
yo kyle , you got the right ideas and the right questions but the whole larger wattage = more penetration/ better spread is not how it works , i mean it does a little but nothing on the scale , the penetration/ spread is left to the optics you use on your diodes IE the lenses ,60 degree is direct and great for penetration where as 90 still isnt bad but has a much more spread out array of light .... theres 120 degree lenses as well havent seen much done with em yet. you are right in the sense that a 3w diode has better penetration than a 1w with the same lens but if it was a 3w diode with a 120 degree lens the 1w wiith a 60 would probly do better on penetration. cheers man hope this helps :D
 

richinweed

Active Member
Best of both worlds, right? Brute force of the HPS and then slamming the plants with the LEDs specific spectrums. I wish I could run a CMH/HPS with my panels, but where I'm at it ain't gonna happen. Someday though.
....fran it seems that the two work well togeather on a 6x3 table, im impressed to say the least, for well under 1k consumption....wow who would have thought [email protected] have heard that optimol is 100 watts per square foot of floor space....but am running far less myself right now , im on the same quest as U my friend....and out of all the things ive dickered with, the small hps led combo has shown promise ..
 

kang420

Well-Known Member
lumans stack...U can clearly see this in overlap areas in the light footprint...also i have used both hps and led...evan a 150 watt sunmaster hps will blow away a blackstar 240....130 actual watts......
I call bullshit all over that mate, i have a 250watt sunT hps with hood and the blackstar 240 2012 flowering model blasts out more light and has better growth than the 250 hps, while only drawing 130watts of power, they have the diodes lenses at 60 90 and 120, 3w chips there no way you would yield more with a 150 hps than this blackstar
 

Stonefree69

Member
I'd like to try and answer the question on how much light a plant uses (for HID anyway), it's 50-100 watts/sq ft. The sun peaks at around 100 watts/sq ft at noon on a summer day
(more or less depending on longitude). So the average throughout the day is about 50 watts/sq ft during the grow season, which growers strive for as a minimum to achieve decent yields.

So I'd say 100 watts/square foot is about the maximum a plant would effectively use. Perhaps a plant can get 125-150 watts/sq ft but it could be diminishing returns when it comes down
to money spent on watts/gram. An interesting question would be to see how much more 75 watts/sq ft of light would yield vs. 50 watts/sq ft or the point of diminishing returns going from
50 to 100 watts (or more).

As far as yields with those watts, or what wattage each plant individually uses, it could vary depending on number of plants grown under the same light(s). With say a 1,000 watt light and
a decent grow setup, it will yield x amount of grams whether it'd be 4 plants or 50. At least I know this tends to be true w/vertical grows.
 
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