LED vs. HPS

[Keith Lake]

I'm thinking about going LED when upgrading our old HPS system this year, but not entirely convinced yet. Can someone point me to some LED resources?
Thanks in advance~ruralgirlz

There are quite a few nice journals around that have proved LED's do a fine job. Couple comparative journals below...

300w LED - Sunset Kush

300W LED vs. 400W HID Demonstration

In my opinion there has never really been a serious argument that they weren't adequate for vegetative growth. In the early days the debate was over whether they could flower reasonably, but this has been put to bed.

The last remaining argument is cost and efficiency. For the indoor gardener on small to medium scale they seem to be at least as efficient as HPS on a electrical consumption basis, but the capital cost is still higher. When the light footprint is optimized for plant count then 1 g/w is a reasonable goal, with 1/2 to 3/4 g/w being typical performance for non-optimized gardens or beginners.

Typically, the LED has been in the defensive position (people questioning whether it was up to par with HPS), but a newer argument has been emerging that the LED trichome production and effect may be more pronounced than with HPS. I've seen this statement made both subjectively from trimming and smoke tests, as well as single-sample quantitatively with equivalent input yielding higher hash output with LED (all else equal).

To make a long story short, no exploding bulbs and if you can afford the initial purchase price the latest generation of lights are pretty effective.

 

[lbezphil2005]

Are there any completed grow journals using the Black Dog led panels? I would love to see the results.

Okay, while his lights I feel are better than most of the others, as far as design wise, his problem is they are made in china, and are not well made. I paid 1600 for my bd700, 3 months in the power cord shorted, got a new one myself, now 2 months after that and one set of drivers are out and he wants me to unplug the light and send it back, he says it will take 1 or 2 weeks, thats what he said originally when I bought the light but it took 5 weeks for it to get to me, can' trust his turnaround time because it's CHINA he's shipping the lights back to fix!! He's sending me the part to fix myself but that will void his piece of shit 3 year warranty. DONT BUY BLACK DOG LED just because of the warranty factor. He really needs to provide a loaner light, something because of the timeframe of his repairs. I am in the middle of a continuous grow, how you supposed to pull your light for a month and have it still come out is beyond me.

 

[PetFlora]

I replied to over an hour ago, but do not see it so...

I had 2 UFO 90s go bad during mid flower. The company replaced both, but offered no loaner... They did allow me to purchase a new one to use during the repair time, and credited me back when they were returned.

Those issues aside, my UFO is old by current offerings, but does a real nice job for a small stealth user.

Stability and Customer Service are what is primarily holding back buyers.

 

[lbezphil2005]

I know, bro, I'm sorry I bought the thing now though. If they were a little better on their warranty I'd reccomend them with no hesitation whatsoever, but seeing how he is doing it, I just can't reccomend it. Stick with glh, integrity matters bigtime with me.

Update: Now that he knows I am pissed off he won't send me the part, now he says because it's a high voltage piece of equipment he can't risk electrical hazards by having me fix it myself, isn't that hilarious!! And he knows I am a disabled industrial electrician and Army trained electronics tech, gotta love it!! STAY AWAY FROM BLACK DOG LED!!!!!!

 

[camplo]

For about 350usd I have 2 x 200w red 660nm leds with matching water proof power supplies. Or I could get 2100k or any fricken spectrum I wanted. Did you know you can have to much blue light and it will stunt the benefits of the blue light? Did you know there is a consistent amount of blue light no matter how much red light that = the sweet spot for blue, Now ya didn't. Fuk this 200 set of 1 watt leds, 100 2watt leds. Whatever. Just like 2 100watt does not = the power of 1 200watt. 200 - 1watt leds wont amount to have one 200watt. You could even get a 400-500 watt single led. If you can figure out how to keep it cool your good to go I guess.

 

[camplo]

Further more these high power led didoes are all SMD which is the newest technology and led standard in china. SMD aint nothing special, it is way better than the past technology that used an epoxy covering but don't be fooled into buying a new smd grow panel off of ebay or anywhere else in the USA. You will pay a premium price for something that is just run of the mill in china. Do you know how many LEDS are in china. They are everywhere in abundance. They offer different quality grades even for different prices. Goes a lil something like this: a: 125-145lm/w b: 105-125 lm/w c:85-105lm/w. I got b grade at .57 a watt. An a grade with a 2100k temp will contend with some of the best HPS in efficiency. I think a HPS that does 150lm/w at 2100k is still more efficient than LED that ranks 125-145 at its most efficient temp something like 3500k or 6500k. . I got b grade because I figured it is 105-125lm/w for white light, at 660nm itll be great on the PAR. A grade is about .90 cents a watt. Even if you still want a panel with many low powered leds its so much cheaper straight from china. Expect to pay very close to 1usd/watt for a finished custom spectrum panel. LED has one great advantage over HPS that is over looked. The ability to have a powerful light that you can sit on top of the plant without setting it on fire. Not to mention no serious cooling needed and easily customized colors and spectrums. If I had a 400watt HPS and a 400watt single led diode both at 2100k with matching lumens the LED could out produce the HPS just by moving the light closer to the plants than the HPS could ever be without burning the plants, which would greatly improve the efficacy of the light to the plant. This is my hypothesis. Discuss amongst yourselves.

ps I also propose that since the leds dont give off giants amount of heat radiation like HPS extremely efficient reflection could be used with creating hot spots that set things on fire.

 

[Bill C]

For about 350usd I have 2 x 200w red 660nm leds

For the same price, I can buy a 600W HID with a switchable MH/HPS ballast, both bulbs, & a sealed hood.

with matching water proof power supplies.

You got me there. The next time I try to grow underwater, I'll think of how smart you were for getting waterproof PSs.

Or I could get 2100k or any fricken spectrum I wanted.

There is more to light than spectrum.

Did you know you can have too much blue light and it will stunt the benefits of the blue light?

No, I did not know that. But then again, I don't have that problem with HIDs or T5s.

Did you know there is a consistent amount of blue light no matter how much red light that = the sweet spot for blue, Now ya didn't. Cause you guys don't do the research. Fuk this 200 set of 1 watt leds, 100 2watt leds. Whatever. Just like 2 100watt does not = the power of 1 200watt. 200 - 1watt leds wont amount to have one 200watt. You could even get a 400-500 watt single led. If you can figure out how to keep it cool your good to go I guess. Anyone could figure this out and I'm the only one posting about this? really?

It was fun for a while, but I'm getting bored with this.....

 

[camplo]

Chronic, someone has convinced you that they dont make full spectrum leds. Let me enlighten you......They do....

The only thing that makes HPS great is its efficiency at such a warm color.

LEDs at current have surpassed metal halide in efficiency.

You dont have to get a water proof power supply. It woul dbe 15 bucks cheaper for a regular one. It just makes sense to me to get the waterproof one. safe>sorry.

Just to recap. A 250watt led vs a 250 HPS both sources at say 2100k, will produce identicle results. The best efficiency ive seen quoted for HPS is 150 lm/w and the best efficiency I've seen for the high powered led is 145lm/w.

LED does have the potential to replace HPS if It can either surpass HPS in efficiency or prove that High intensity light at specific wavelength will make it more effective. Like I stated earlier, a large group of small lights cant create the intensity of a single source of the same accumulated power. So if single out spectrum is a benefit, these light panels with 1-2-3-4 or even 5watt diode ain't gonna do it.

So unless there is something else that I dont know that makes HPS lamps so great other than its efficiency and color, LEDS are already better since they last so damn long.

 

[PetFlora]

A good cheap find for LEDs, but are they good for our needs?
American DJ Homepage

 

[Lunatic Lumen]

wow thanks for the info on the LED, they look to be catchin' up but still got some distance to clear, especially on the $

 

[akaman]

wow thanks for the info on the LED, they look to be catchin' up but still got some distance to clear, especially on the $

It seems everytime something new comes out it has to be expensive to purchase. I think it's about the $$. remember when cd's first came out, expensive, then we find out it only cost a few cents to make em yet the record companies were charging a arm and a leg. All about the $$.........BUT.... Led's do work, I can't argue that.

 

[williboy]

Sorry about the "add". Camplo' I think I need some reaserch. Wouldn't the ability of an equal PAR value LED be better to an HPS/HID bulb since it can be safely so much closer to our little friends. This seems pretty apparent when useing S.O.G. or Scr O.G. techniques to me, certainly removed some HPS from some gardens so far in NorCal. But I got to tell ya I think some of these growers are so amazing they could probably grow one in the palm of their hands.

 

[williboy]

Sorry jumped the gun on that question to Camplo, answered pretty well the question regarding how close you can get to your plants, LED vs HPS. I've recently seen a good drop in several LED manufactorers prices. Top end from $2000 per array down to $1300 for one maufactor. Several new guys in the mix with entries that look pretty well made too. Perhaps if this takes off a bit the cost of HPS systems can come down too.

 

[saywhat]

This might be a dumb question I dont know sh#t about growing but i'm doing my best to learn and I really want to make sure I know what i'm doing before i start and do it the best I possibly can.

Question: Would it be effective to use both an HPS lamp and LED together? As far as getting the best results.. Would that work?

 

[Keith Lake]

Sure you could but that would essentially be adding cost without commensurate benefit. The whole idea of LED.is to accept a higher equipment cost in return for a lower heat, lower electrical demand, less detectable grow.

The LEDs are great for the veg stage and just proving themselves approximately equivalent at flowering. The HPS may be easier for a beginner, but HPS bulbs are a bit more dangerous (can explode)

You might want to consider CFL for a first try. Of course a lot of the decision making process should involve consideration for the scale of he grow you'll be taking on. The larger it is, the more you may want to consider metal halide or HPS.

There's a link in my signature to our "how to grow" forum, I'd suggest you read through this a few times before opening the wallet. As they say, plan before do

 

[KloneKing]

I've been studying up on a few led's and found a lot of scammers when it comes to 1w,2w ,3w and 5w diodes. One thing is for sure is that none of them throw down the initial lumens as most hps, and its pretty easy math to figure out how many a certain led puts out How many diodes x lumens per diodes.

 

[TorturedSoul]

I've been studying up on a few led's and found a lot of scammers when it comes to 1w,2w ,3w and 5w diodes. One thing is for sure is that none of them throw down the initial lumens as most hps, and its pretty easy math to figure out how many a certain led puts out How many diodes x lumens per diodes.

You may have noticed in studying individual LEDs and their lumen output that some wavelengths have a higher lumen rating than others even though both their wattage and gross light output are comparable?

Keep in mind that the term "lumen" is one of those artificial things, created by humans for use in situations dealing with human-things. Specifically, when comparing two light-sources - of any type - that have different lumen ratings... A greater lumen rating in and of itself only means one specific thing: The device with the greater lumen rating appears to be brighter to the human eye.

Lumen is not a measurement of the amount of absolute light output (that would be "gross radiometric output," I believe). And it is certainly not a measurement of light output that is usable by plants for photosynthesis (et cetera). That would be PAR (photosyntheticly(sp?) active radiation).

I don't often see PAR ratings for LED panels or light bulbs (I noticed that Lumatek publishes PAR specifications for their brand of HPS bulbs). I would tend to expect that the manufacturer/seller of a setup such as an LED grow-light panel would advertise the PAR rating for its products. i would expect it because, hypothetically, it would be much easier to create a high-PAR LED panel than to create, say, a high-PAR HPS or MH bulb. With an LED panel, the manufacturer is able to pick and choose what wavelengths, what wattage, what lens, how many individual LEDs and of what ratio, et cetera.

The fact that more LED grow light advertisements do not quote their panels' PAR ratings tells me that they either have something to hide or that they remain clueless. The fact that some will quote a lumen rating but will not quote a PAR one... Well, I suppose that makes it easier to give them the benefit of the doubt that they aren't so much scammers, that instead they just don't understand the whole point of putting a light over a plant, lofl.

Personally, if I was offered an LED panel that produced the same lumen as an equal-wattage HPS produced, I'd probably turn it down. I'd expect them instead to include more wavelengths that are useful to the plant and less wavelengths that my eye perceives as being brighter (such as green and yellow).

The hypothetical ideal LED grow light panel will have a much lower lumen rating than a comparable-wattage HPS (and a much higher PAR rating). HPS bulbs in general are inefficient grow lights; they manage to produce the harvests that they do simply because they do have a pretty good gross radiometric output (or as my ex-wife once remarked, "That sure is a hella-bright closet light.")

For more on what I mean with lumen, here are a couple random references from my browser's bookmarks:
Lumen (unit) (Wikipedia page)
Human eye sensitivity and photometric quantities (a .PDF hosted at Rensselaer Polytechnic Institute's Department of Electrical, Computer, & Systems Engineering site)

I just realized that I've forgotten what my point was <OOPS!>. Tired. Couple days past my bedtime.

 

[SirSmokeALot-]

I'm planning to buy a 90W LED grow light, and i wanted to ask what you guys thought of this one ?

I have been reading and watching videos of reviews and it still seems that when ordering you cant really know what you will get. With HPS and MH its alot more straight forward and fool-proof, but with LEDs its a bit complicated. Also the fact that almost all of them are made in China is a bit worrying.

The lifespan of LED lights is 50000+ hours, but i bet those fans will fail sooner than that. Also i was wondering how loud would those fans be, its difficult to tell from videos i have watched.

 

[bcgrowforu]

If you were to pick a led light/company would you mind pointing me in the direction by chance, I've been going in circles lol. I
have a 5x5 room for bud and same for veg

 

[JokerJohn]

Hey guys brought this 90w UFO the other day.

Not a cheap knock off one as it was brought from a Hydroponic store
Just wondering if anyone has delt with these before and has any ( positive ) info they can share

Thanks

JJ