Grams per watt, LEDs outperform HPS

forgetiwashere said:

i simply dont believe that the plants dont use all this light.. i grow cmh to get the full spectrum of colour and i can tell u i have seen a marked improvement in plant growth. the plants are stockier, happier, more robust and hardier. i actually found that sick plants put under cmh will recover quicker than plants under hps or mh.

also i challenge you to put your led panels to the plant test. get a single plant and put it under 2 lights, an led panel on the left and a cmh on the right and i guarantee within a day the plant will be reaching for that cmh with every leaf it has.

then tell me they dont respond to the full spectrum of light

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I'm doing this now...sorta. 2x2 tent, Pro-Grow 180 covering two plants and 150w 3000k CMH covering the other. I can tell you one thing: the CMH puts a lot more heat off than the LED panel, and the PG 180 pulls around 150 watts. Only for flowering however, and only about 3 days so far. Will see how it goes with time.

Endur0xX said:

hahahah 46 oz from 600W, try 30

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Nah man, you try again...page 24 of that thread post number 235...46 ounces off a 600 watt hid..9 weeks start to finish

brotherjericho said:

I'm doing this now...sorta. 2x2 tent, Pro-Grow 180 covering two plants and 150w 3000k CMH covering the other. I can tell you one thing: the CMH puts a lot more heat off than the LED panel, and the PG 180 pulls around 150 watts. Only for flowering however, and only about 3 days so far. Will see how it goes with time.

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good stuff bj you doing a journal

I think I have seen it before, I did the math wrong at first I thought you meant 4lbs, but regardless, you got to be dedicated to do a setup like that, I wonder what that weed was like potency/taste . It cannot be done with LEDs at the moment I would have to agree.

I agree that HID may produce a higher yeild of bud mass, but when i grew the same bag seed strain under HID (430w hps) and now its been grown under 430watts of led (bs500,Bs240) and the bud potency is double maybe triple. Now there has been a 1 year difference between cuttings that i used. HID cuttings taken from the same mum when it was 6 months, but led cuttings taken from the mum when its 1.5 years old. I've read that potency increases as the plant gets older? but 2 - 3 times as much? Or maybe i have become a better grower? Techniques have improved? Only difference is i have added shooting powder, GH floranector, Earthjuice catalyst. Maybe the extra organics during the end of flowering (I eliminate all chem ferts at the end except 0.4ec canna AB to maintain coco Cation echange with ca and mg) has enchanced flavanoids and terpene production and is much more potent compared to growing with just Canna ab, rhizo and pk 13-14. Quality and potency seems increased due to LED specifically targeting the flowering spectrum. Well this seems the case on my end, others may differ, but been growing for 7 years now to control back pain and 1 year with LED and quality over quantity any day in my books.

Also noticed that plants grown at higher tempretures with LEDS do not display as severe heat stress symptoms as plants under HID ( e.g 95f tent temps LED compared to 95F tent temps HID), HID has alot of radiant heat and at higher temps this radiant heat can burn/bleach pistils/calyxs/leaves with no problem unlike LED at the same tempreture.

Peace to all and happy growing.

We pay 40cent per kw/h so I have to look at more factors than just the purchasing price of the unit,

World electricity prices by country :
http://en.wikipedia.org/wiki/Electricity_pricing#Price_comparison

I've made this table of the price of electricity(using 0,11$/kwh as ref.)
when using a 1-1000 watt growing 12, 16 or 18 hours - per day, week, month.
for some quick comparison.

ssj4jonathan said:

Dont forget the extra $150 for a blower and duct work, and another $300 for an portable AC unit, and a 3x higher electric bill per month, alternatively, you could stick to winter only grows and let nature cool your red hot bulb. $300 in leds will get you something that pulls 240 watts of power vs $300 of HPS which accounts for a 1000 watt mag ballast, a decent hood and a bulb. Why not invest your money wisely and buy 4x 300 watt led panels to match the wattage your willing to consume 12 hrs a day. When harvest comes around, all the extra money you spent on LEDs would be recovered by all the extra buds your plants would make. LEDs are just way more efficient at giving plants what they need, cant say the same for hps, most of its power comes in the form of IR, UV, green and yellow light most of which plants dont need.

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First, let me state I no longer use MH/HPS, I have a UFO 90 for cloning/seedlings, and HO T5 for growing/flowering, using specialty aquarium bulbs, which allows me to simulate precise LED spectrums.

I disagree with your assessment "... IR, UV, green and yellow light most of which plants dont need". This line of thinking has actually held led back. MJ does benefit from them, (see HGL quote below). The primary issue is hps's radiant heat. I can place my plants within 4" of my 432w HO T5 bulbs.

Quote from HydroGrowLED

"Additionally, we learned that plants absorb small portions of light between their photosynthesis peaks, so we added white to our spectral configuration to fill in these gaps. We also added far-red light to extend photoperiods into the night cycle, speed up photosynthesis, and provide other benefits to plants such as cell regeneration and repair. After much deliberation, our spectral ratios were set to 70% red, 10% blue, and 20% white."

What I do not like about most led fixtures (some are addressing these):

1. inability to change out led clusters. Relying on fans instead of designing fixtures on large heat sinks (EVO).
2. Fixture dimensions: They should be designed like EVO- thin rails.
3. The ability to switch spectrums o/o to accommodate various stages of growth like Hans' panel ledgrow.eu
4. Difficulty to replace fans which will die long before the diodes

I am lighting a 2 X 4 area with 432 watts for less than $500, including a variety of special spectrum bulbs for both veg and flower

I would love to try but for now Ill take 100 less grams for 2500 less cost of the lamp.

This study is obviously biased toward HydroGrow. Yes, they are a good company who make some of the better lamps. But they cannot claim to speak for the entire market.

Having built a couple DIY LED lights myself and having personally seen results not only from my grow, but from all over the internet, let me say two things I know for sure.

1. A properly designed LED lamp will grow excellent buds, as good as or better than HPS in quality. Properly designed is the key here; thermal management and spectra must be dialed in.
2. The LED market is a confusing minefield with wildly varying results and prices. One google search will make this abundantly clear.
3. There is no "bad" HID lighting. HID lighting produces consistent, large and potent results. The difference between one 1000w HPS and another is nil.
4. There are bad LED lamps. Bad LED lights produce too much heat, low lumens and inconsistent spectra resulting in leafy plants and small, airy buds. (Blackstar I'm looking at you)
5. Good HID lights cheap, good LED lights are NOT.
6. Bad LED lights will fail prematurely. Yes, their lumen output will be reduced and so will their lifespan due to bad thermal management. There goes your "energy saving" investment. There is one company I just read about implementing a buyback program. Wonder why?

So basically for the average hobby grower HID is still the obvious choice. Heat is really the only downside. Put a 1000w HPS up against the best LED light on the market and I guarantee you the HPS will be the better looking and yielding plant. LEDs cannot match the intensity of the 600 and 1000w bulbs; they just can't yet.

Now if you make your own using good Cree or Osram LEDs, now we're cooking with fire. Give me 800w of high bin Osram Golden Dragons on a giant heatsink and watch it outperform the best HPS. Unfortunately the saying, "if you want to do something right, do it yourself" applies to LED tech at this point in time.

what is the best led light available bassclef?

Corso, I've seen very decent results with Hydrogrow lamps. Just a quick run through their site claims a 95F operating temperature (enough to not kill the AllinGaIP reds) and use Bridgelux LEDs which are better than the no-name Chinese kind. Their 600w unit also goes for a cool $2000 so keep that in mind. The decent lights seem to be the most expensive.

But there is no "best". Thermal management is problem number one, followed by type of LED used and spectra. If they have those bases even remotely covered the light will work well and last.

Check out the difference in light output from this one test when the junction temperature gets 10C above it's limit. It's from Bergquist's website; they specialize in thermal management solutions for LEDs.

Junction temp goes from 32C to 42C, light output jumps from 630 lumens to 110 lumens!!!

.

bassclef said:

Corso, I've seen very decent results with Hydrogrow lamps. Just a quick run through their site claims a 95F operating temperature (enough to not kill the AllinGaIP reds) and use Bridgelux LEDs which are better than the no-name Chinese kind. Their 600w unit also goes for a cool $2000 so keep that in mind. The decent lights seem to be the most expensive.

But there is no "best". Thermal management is problem number one, followed by type of LED used and spectra. If they have those bases even remotely covered the light will work well and last.

Check out the difference in light output from this one test when the junction temperature gets 10C above it's limit. It's from Bergquist's website; they specialize in thermal management solutions for LEDs.

Junction temp goes from 32C to 42C, light output jumps from 630 lumens to 110 lumens!!!

.View attachment 2208215

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Note on top of the image it says: "Light output of the same LED die on different circuit board materials at a maintained die temperature of 80°C (176°F)"

better off having my brother (electrician) build me a couple?

Looks like the test come from this site or some like it:
LEDs - Temperature Effects
http://www.bergquistcompany.com/thermal_substrates/LEDs/temp-effect.html

It also looks like it's a test of thermal clad versus FR-4
and it sure looks like FR-4 is a crap -that's good to know.

But looking at the PCB's called FR-4 like this witch has holes in then where the LEDs heat transferring metal part goes through
I can't see why thees would be crap if mounted on a proper heat sink with good thermal paste. ?

And the reason this is getting my attention is that the new panels like Apollo 6-8-10


Is using what looks could be FR-4


I don't think the test is applicable to our grow light(1&2gen.) with the led mounted directly on the
heat sink and not on a pcb.

Rasser, I think it would be difficult to fill in the gap in the FR-4 holes there with something electrically isolating. Thermal adhesive might work, but you'd have to goop it in there; not really the best way. And if you use Kapton tape, you also suffer thermal transfer penalty.

The challenge is transferring heat quickly from the thermal slug of the LED (on the bottom) into the heatsink quickly with the thinnest layer possible while also electrically isolating it. Currently the Bergquist stars have the best thermal conductivity in this area, as most DIYers mount them to the heatsink with good thermal epoxy.

I personally use wakefield delta pads, they are much thinner than the bergquist stars (.007in) with the same thermal conductivity (1.3W/m-K) and electrical isolation. FR-4 thermal conducitivy is much less at 0.3W/m-K.

Rasser said:

I don't think the test is applicable to our grow light(1&2gen.) with the led mounted directly on the
heat sink and not on a pcb.

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Absolutely it's not, it wasn't meant to be a direct comparison. I just wanted to show how LEDs (especially reds) drop off a cliff with light output once they reach ~40C or so. A heatsink will reduce temps for sure. Problem is if the fans or enclosure isn't great at getting rid of heat, or the heatsink is too small, and the whole unit heats up.

bassclef said:

Absolutely it's not, it wasn't meant to be a direct comparison. I just wanted to show how LEDs (especially reds) drop off a cliff with light output once they reach ~40C or so. A heatsink will reduce temps for sure. Problem is if the fans or enclosure isn't great at getting rid of heat, or the heatsink is too small, and the whole unit heats up.

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Just thought for a moment that "Junction temp goes from 32C to 42C, light output jumps from 630 lumens to 110 lumens!!!" was correct.

Looking at the chart from the thread BS is doing it wrong I don't see that a dramatic effect on light output vs. temperature.

In the thread: PAR Quantum Light Meter - LED vs. HPS - Cold start flux output vs. Running
My lamp drops 4.5% from 457 to 436umol from when starting the unit to it has been running for 10 min.

That tells me that the leds JT. don't get to high and the heat transferring system seams to be working fine.