Are LEDs Misunderstood?

[knna]

Yep, the transformer thing is a big problem. Not because good transformer/driver are not avalaible, that they are, but usually using them raise the cost a lot.

So most lamps on the market right now, and AFAIK, all chinese ones, are using very bad drivers. Low efficient and little reliable.

Probably the main problem of chinese lamps is this. On a very high percentage of lamps, either the driver of LEDs either the fan's transformer fails. Of course, there are still many that continues working fine, but its a matter of luck, and I think those lamps cost big bucks to depend of luck.

Buying on sites with guarantee and that are there when some problem arise is a must

 

[knna]

if you had checked my old account posts.. 200-340nm and 680-800nm ratios are unknown. 340-420 and 630-680nm is unsure but the main idea is very stable - im still after the old calculations because there came no new factors yet but in the end only practical tests can show! and me, nor anyone else without extreme buget can test it yet but having real numbers not just "use white" is a good start

Of course actually many people have found some spectrum distribution that works. The one we are mostly using is having near double efficacy than HPS spectrums (same amount of photons producing double yield), that probably is near the maximun (can we 3x the efficacy of photons? I havent found any similar on botanic literature,but who knows, all this is so new). But we still need to know more about effect on taste and high before saying a given spectrum is the best. We need to clear if high irradiance setups works better with a different spectrum than with low irradiances, and so on.

The spanish group is using some different spectrums so we are learning fast, but I think we need to know a lot more before being able to say how is the "prefect" spectrum to grow cannabis.

 

[unthing]

Hi Knna

I'm interested about the possible adjustments that your test group has made to adapt to led gardening in terms of soil mix (more drainage needed?) or nutrient levels and ratios in general in all common mediums soil,coco and water. Is it even necessary?

 

[knna]

Hi Knna

I'm interested about the possible adjustments that your test group has made to adapt to led gardening in terms of soil mix (more drainage needed?) or nutrient levels and ratios in general in all common mediums soil,coco and water. Is it even necessary?

Some adjustement is needed, but its not critical. Most people started using exactly the same they used when grow with CFLs or HIDs, and many had not any problem. But some do, in general related to less transpiration of plants and lower water uptake.

In general, we agree on the need of using slightly higher CE levels. Or at least, of increasing Ca in the mix.

Other adjustement is related to temperature. LEDs raise so little the room temperature than some growers had to use a heating element in order to get a good environment for growing during the winter. Most grower had their grow areas between 20-25ºC (68-77F), and in general in low 20's (about 70F) that is a little suboptimal for MJ growing and results on slower growth rate.

After seeing this problem with temp, I call growers wanting to use LEDs for growing to check their light off temperature. If its low, it makes sense to use hybrid systems (LED plus CFLs or HID). On those setups, where LEDs are just a part of the lighting, there is no any adjustement required in comparision to standard growing. In this trend, using LEDs as suplementary lighting for setups already using other type of lighting is the easier way of using them, as it not implies a learning curve.

Im liking specially the results from HPS plus red and blue LEDs. Spectrum is excelent, temperatures are very good, no any adjustement is required. As the watts density (W/sq ft) of HID used is lower than on HPS alone setups, heat is way more manageable, but the efficacy is strongly improved. Its a win-win solution, and way cheaper than the LEDs alone way.

Lately when somebody ask me because he want to go LEDs, I ask them what lighting is on use on their actual grow rooms,in order to see if its possible to use it. Some people is using a large HID but keep an equipment of less watts (they started with an smaller cab, for example), or they can enlarge thier grow area, so they can keep their actual HID lamp in use and add LEDs, obtaining very nice yield improvement at little cost.

 

[knna]

Along the thread, there has been some complaints about the noise from fans used on LEDs lamps. Its clearly disturbing, and more for people that went LEDs for stealthness.

I dont use fans on my LED lamps. Not only due the noise, but mainly for reliability concerns and efficiency.

If you design a lamp for working with a fan, in case the fan fails (that usually is just a matter of time, as many fans has an average lifetime shorter than a good LED lamp should have, and often the fan's transformer fails earlier yet), the full lamp is compromised. 6h working without the fan probably damage LEDs, in a way they emits way less light than they should emit or simply get burned.

On the other hand, I think one of the best advantages of LEDs is the possibility of distributing them along the grow, thus getting a very even light distribution. Using fans on this modular designs is not practical (each module should have their own fan).

So I use aluminium heatsinks, calculated to not need any active cooling. Its not a so expensive solution as many people thinks. Although it depends of the shape of the heatsink, its perfectly possible to use 1Kg (~2lb) of raw aluminiun for each 65W or so. Price for raw aluminium (1050 alloy, 99.9% aluminiun, works perfect) may range for 10-20€ eack Kg (on the retail level). So a 120W lamp can use just 2Kg of aluminiun, costing about 20-40€ (27-54$), while saving on fans and its transformers. Very little cost increase for getting a great improvement on reliability, save watts and eliminate noise.

From my viewpoint, for horticultural applications to use fans as cooling method is no sense. It only offer advantages on the short run for the seller: higher profit margin, lower weight reducing shipping cost, easy design (on the long run, I think it dont worth for the seller neither, due the reliability concern, as far as the seller wants to stand in the bussiness and not take the money and run). For the user, fans as only cooling method only have disadvantages.

 

[unthing]

Thanks for the answer. I agree about the fan issue in design.

Another thing:

Can you give some general % about how much red and blue leds you (would) use to supplement the hps? Such combination might still not be practical for big grows, but for personal grows, why not?

Edit: I find the idea of cmh+red leds fascinating

 

[globel]

MrWags has documented a lot of good grows here on ICmag ... He gave his back ... thats enough for me

thanks for that info...

I guess I'm just gonna have to wait longer

Game Over.

 

[FreezerBoy]

Hardly. The games just getting started.

 

[asde²]

for hid less than 400w i suggest to use cmh (a efficient one, not retro white, they are crap) with ~4k color temp using "hid wattage/~3" led @ ~640nm, for 400w hps (remark) and higher i think using blue led "hid wattage/10" blue spectrum (360-470)

 

[Auto Pimpn]

Hello everyone!!

I would like to make a point not really brought up yet.

Which lights are better for QUALITY?

HPS/MH or LED??

Quality(potency) DIRECTLY corresponds to Quantity (yield).

With higher quality, lower quantity is needed to smoke.

If I only need to smoke 2 g per day vs 4 g per day, then Quantity(yield) has little relevance to me.

I would rather have a few ounces of some super dank than a pound of schwag.... Wouldn't you?

IMO, yeild is partially insignificant in regaurd to Growing Marijuana for Personal use. Unless you are a commercial schwagg peddler of course.

We smoke it to get high right? I know I do.

My point is that you can keep adding light, or get a more intense light but untill the light effects quality rather than quantity WHO CARES which yields more?

By quality I mean the percentage of psychoactive compounds present. THC CBD CBN ect....Not bud density or looks.

The most potent marijuana I have ever smoked is from outdoors.

SO which lights produce the most potent buds?

Is there even a real difference in potency with HPS/MH vs LED??

I would like to see potency (TLC or similar test) data from the same strain grown under different lights, and then we can say which lighting system produces the most potent product.

Like I said earlier, which ever system produces more buds doesn't make it the best system. I prefer better quality.

Thanks for all the great info all!!

 

[FreezerBoy]

Hang in there. That's why these experiments are going on. Give them a chance to finish a grow. The greatest smoke in the world is useless if it gets you thrown in jail. There are myriad reasons why outdoor growing might be the very worst of all possible scenarios. I'll happily take a .0000005% cut in potency to increase my safety a millionfold.

 

[knna]

If I only need to smoke 2 g per day vs 4 g per day, then Quantity(yield) has little relevance to me.

I would rather have a few ounces of some super dank than a pound of schwag.... Wouldn't you?

IMO, yeild is partially insignificant in regaurd to Growing Marijuana for Personal use. Unless you are a commercial schwagg peddler of course.

We smoke it to get high right? I know I do.

My point is that you can keep adding light, or get a more intense light but untill the light effects quality rather than quantity WHO CARES which yields more?

By quality I mean the percentage of psychoactive compounds present. THC CBD CBN ect....Not bud density or looks.

The most potent marijuana I have ever smoked is from outdoors.

SO which lights produce the most potent buds?

Is there even a real difference in potency with HPS/MH vs LED??

I would like to see potency (TLC or similar test) data from the same strain grown under different lights, and then we can say which lighting system produces the most potent product.

Like I said earlier, which ever system produces more buds doesn't make it the best system. I prefer better quality.

Thanks for all the great info all!!

I think quality is a concept wider than potency, as it includes taste and some other topics.

As for potency, I didnt see large differences between HPS/MH/LEDs. If they exist, are small.

We carried many samples of LED grown pot to the last cannabis fair where in the Canna stand were performing accurate cannabinoid profiles by GC, but unfortunatelly they refused to analyze it because they already had many samples. One grower carried samples of the same plant (a Jack Herer mom) grown outdoors and under LEDs, it was sad we couldnt check the difference.

 

[DankSide]

I wholly disagree, it is about spectrum and penetration, but mostly about irradiance within PAR range. All these topics I have written about to death already. I for the life of me don't see why you guys can't grasp these simple topics. Nowhere else in the world of horticulture but in the cannabis world would one find these types of LED arguments. Even NASA's own studies agree with me! (that is where I get some info BTW...)

Well for me it definitely comes down to price, because it has been shown that the LEDs can veg a plant, I would prefer to have an LED veg cab and save a few extra bucks on power, but I can't do that if an LED setup costs $700.00 and the HID costs $200.00

 

[FreezerBoy]

but I can't do that if an LED setup costs $700.00 and the HID costs $200.00

There's more to cost than purchase price. A gallon of vinegar is $3. A quart of pH down is $15. But a quart of pH down is about 50-100 times cheaper than a gallon of vinegar in actual usage.

I don't pretend to know how it all breaks down price wise with HIDvsLED but, purchase price alone tells us nothing.

 

[renz]

Well for me it definitely comes down to price, because it has been shown that the LEDs can veg a plant, I would prefer to have an LED veg cab and save a few extra bucks on power, but I can't do that if an LED setup costs $700.00 and the HID costs $200.00

Markup on LEDs is like 2x retail cost for the emitters, you can just throw them on some aluminum heatsinks (old used up audio amplifiers
are a great source) and try them out for way less.

90%+ efficient switch mode adjustable current regulators can be had for around $15 and will drive between 20 and 30 watts of LEDs.

Else you just have to wait a couple years. If cost is an issue and you *need* results get HID. But if you're just curious and don't want to spend the money, you really done have to pay $600 for a 90W system. It's prob 90W draw anyway, not 90W into the LEDs.

And they're little emitters anyway cant do anything except SOG and similar stuff. I live in California and there is a per medical user plant limit. To be legit without being caretaker for a ton of people, you have to grow big. I've heard people getting good results with between 2 and 3 months veg using buckets. Little LEDs probably aren't going to do much in that situation.

ALSO, I'm still waiting for people to volunteer photos of ripped apart consumer LED arrays so we can see drive methods and manufacturing quality.

If you want to send me yours to pull apart and document I promise I'll be gentle! Heh...

 

[snaggy]

There are many DIY led circuits available already on the net.

We are talking led's.

But are we talking about crappy wattage ( 0.5w) LED's using only dual-band ( red & blue )?
Or
Are we talking about multi-spectrum ( could contain any combination of violet, royal blue, blue, amber, orange-red, red, ir, and white ) LED's with 1-3.5watt Cree LEDs?

There is a huge difference here in spectrum, wattage, and I would assume the end results..

Kinda of hard to follow anybody's opinion, and take it as real info here, because I think everybody is talking about crappy 5 yr old LEDs.

Before we can even discuss LEDs, we need to specifiy what LEDs.
Otherwise I do not even know if we are talkin about a Chevette or a Corvette.

 

[habeeb]

The greatest smoke in the world is useless if it gets you thrown in jail. There are myriad reasons why outdoor growing might be the very worst of all possible scenarios. I'll happily take a .0000005% cut in potency to increase my safety a millionfold.

this is so true!

I'm sure most grows are small personal grows, so LED's are gonna fit for everyone ( side lighting for big grows, and am sure most small grows will change over to LED )

 

[PetFlora]

I think snaggy nailed.

As I read lighting blogs, it becomes clear (to me) that in order to approximate sun light mj (or any indoor plant really) needs many spectrums, including UVb. Perhaps what we need (at this time) is a light salad: A mixture R/B LED, CFL, and UVb.

Someone is probably already doing this.

My questions begin

1. Which light do you position where?
2. How many watts of each per cft?

 

[unthing]

edit: incoherent crap

 

[unthing]

From the grows I've seen and my own lil experience, I don't have much interest for farred. The effect it has seems to be marginal at best even thou in literature it has important effects on various photosystems etc. Uv, now that's interesting. Those guys that had delayed flowering early on with leds might have had just too little light.

But IMO the general recipe for 9:2:1 red,blue and white that KNNA and others have used is pretty good starting point. Ledgirl's recipe is pretty same too. Of course there's those subratios of different blues and reds.

Beyond that my concerns are mostly efficiency(energy conversion to light and to have enough light in general),price and some design points (like cooling the damn thing)