Should I go LED? Please rate this product.

[FreezerBoy]

Jay, you need to check out the LED grows here by: Sleepy, Hazy, VerdantGreen, Blazeoneup and others who've used LEDs for flowering with great success. If you choose not to use them, fine but, there are many here for whom a 600 or 1K would be a disastrous choice of light and for whom LED would be perfect.

 

[woolybear]

Jay, you need to check out the LED grows here by: Sleepy, Hazy, VerdantGreen, Blazeoneup and others who've used LEDs for flowering with great success. If you choose not to use them, fine but, there are many here for whom a 600 or 1K would be a disastrous choice of light and for whom LED would be perfect.

You can also check my grow in my sig. I don't claim its a perfect grow as it's my first after a while, after week four my flowers are looking pretty good.

In four weeks we shall see how my LEDs fared! My goal is 0.5 gram/watt. I am flowering 7 girls under 300w, so my goal is 150 grams or a bit more than 5 ounces.

5 ounces of killer smoke I'm hoping... 5 zips is more than enough to last me 6 months, i'm a light smoker as I have light access to budz and have never had any name-brand weed.

 

[exploziv]

Grown under led:



Not so big buds, but quite potent ones.

 

[sm0k4]

I don't see why people dismiss LEDs when there are plenty of good grows using LED out there.

If you aren't intelligent enough to figure out growing under LED needs a different approach, then it isn't for you. Inexperienced growers have gotten 1 gram per watt. That is way more efficient than some inexperienced growers that start out with HID and get .25 grams per watt.

If you know what you are doing, LED works, you can't argue the amount of journals and pictures that are out there now. Before you could dismiss it as being put out by the companies that sell the lights, but too many people have threads about LEDs. The bad grows always start with bad LED products.

A little research goes a long way. Will LED produce bigger buds? Definitely not bigger than an HPS, but big buds isn't what most of us care about, its the weight per Watt grown. If I can get the same weight with 1/2 to 2/3 the wattage then I will. But its expensive to do it right. Buying a $100 90 watt UFO is a ripoff. You can get buds, but you better supplement with CFL. Taking the LED manufacturer out of the equation assures that you have the best LED light you can make.

If my buds suck under my DIY lamp, I'm going with a 250 HPS in my bigger cab with LED side lighting. Gotta test the waters before I say LED works or doesn't in flower, so far I'm liking the LED performance through veg. On day 9 of flower now.

 

[auto guerilla]

sperr: fwiw, plants use green light for photosynthesis just fine
i cant believe you said that. have you researched this enough, seriously. every scientific study has shown the complete opposite hence the reason for using green lights during dark periods as no photosynthetic activity is activated...keeping it in the dark phase

 

[auto guerilla]

as for led growing they do have great benefits including no thermal fingerprint in infrared scanning (stealth) and less heat which are both great qualities. as for quality of bud i speak only for myself in saying that stretching and airy buds are enevidable but they definetly do deliver quantity. they just dont seem to form dense plants and dense buds. overall i would say 'lacking density' is its only week point. overall not bad lights though. they serve their purpose

 

[spurr]

sperr: fwiw, plants use green light for photosynthesis just fine
i cant believe you said that. have you researched this enough, seriously. every scientific study has shown the complete opposite hence the reason for using green lights during dark periods as no photosynthetic activity is activated...keeping it in the dark phase

Please take the time to study this topic, outside of cannabis forums and cannabis books, before making the claim about "every scientific study". The fact that green plants use green light for photosynthesis has been well known (outside of cannabis growers) for over 40 years. We can thank the likes of Mel Frank, Jorge Cervantes, and other book authors and magazine authors for perpetuating the myth about green light having no photosynthetic activity.

We can use green light at night and not interrupt flowering because green light lacks far-red light; we could just as well use blue PAR range light during flowering a night. The keys are irradiance, time and lack of far-red light (and lack of UV light is also a good idea to prevent cyrptochrome reactions that could affect flowering). That is, the irradiance must be low and the time must be short relative to irradiance. E.g,. the higher the irradiance the shorter the time the plants should be irradiated; and irradiation should not be more than very low. Think about it, moon light is mostly 'blue', not green, and cannabis flowers outdoors just fine...

Check out these links to posts of mine and a thread of mine for scientific info. In the thread I explain the flaws from the chlorophyll A/B absorption spectra; the source of the myth about green light not being used for photosynthesis:

https://www.icmag.com/ic/showpost.php?p=4243102&postcount=57

https://www.icmag.com/ic/showpost.php?p=4243283&postcount=64

Avoid Misconceptions When Teaching About Plants

 

[ak-51]

I don't see why people dismiss LEDs

1. Manufacturers ridiculously overstating their LED unit's abilities. 90w UFO replacing a 400w HPS? Please.
2. Upfront cost is a turn-off to most.
3. Nay-sayer will take into account only final harvest weight while ignoring the reasons you pay more for LED units in the first place: reduced power consumption, (supposedly) long life, reduced heat, compact size.
4. Overabundance of cookie-cutter crap units coupled with lack of definitive information on which ones are good makes buying into a guessing game.
5. Some people are just haters.

 

[Kcar]

This one looks good:

http://357magled.3dcartstores.com/357_magnum_LED.html

 

[spurr]

White LEDs provide some green, not a ton, but how much do plants really need?

I have read a few studies that found ~20% green light is sufficient, and a couple others that found ~20-30% is sufficient. If I were to make a LED array I would shoot for something around 50% red range; 25-27% blue range; 20% green range and 3-5% far-red (720-740 nm; peak of 730 nm).

Granted, one can grow plants without green light, and one can grow plants without blue light, but using the whole PAR range gives better results when the lamp is the only light source.

 

[sm0k4]

sperr: fwiw, plants use green light for photosynthesis just fine
i cant believe you said that. have you researched this enough, seriously. every scientific study has shown the complete opposite hence the reason for using green lights during dark periods as no photosynthetic activity is activated...keeping it in the dark phase

They do use green, and they use green more effectively when red and blue are near saturation levels.

 

[sm0k4]

I have read a few studies that found ~20% green light is sufficient, and a couple others that found ~20-30% is sufficient. If I were to make a LED array I would shoot for something around 50% red range; 25-27% blue range; 20% green range and 3-5% far-red (720-440 nm; peak of 730 nm).

Granted, one can grow plants without green light, and one can grow plants without blue light, but using the whole PAR range gives better results when the lamp is the only light source.

Sounds good Spurr. I will re-arrange my array for the next small test grow.

 

[Sandnut]

LED's are too expensive at the moment.. overpriced and over rated

If they price comes down to a reasonable amount of money compared to how many 400w setups you can get, then hell yeah id look into buying one

 

[spurr]

Sounds good Spurr. I will re-arrange my array for the next small test grow.

Cool, I am interested to see what you think; even 10% green would be better than no green. BTW, do you have access to a quantum sensor and light meter or data logger?

Oh yea, I made a typo: "3-5% far-red (720-440 nm; peak of 730 nm)." should read "3-5% far-red (720-740 nm; peak of 730 nm)."

 

[sm0k4]

Cool, I am interested to see what you think; even 10% green would be better than no green. BTW, do you have access to a quantum sensor and light meter or data logger?

Oh yea, I made a typo: "3-5% far-red (720-440 nm; peak of 730 nm)." should read "3-5% far-red (720-740 nm; peak of 730 nm)."

I wish I had access to a good PPF meter. I can look around and see if any contacts through work would have access to one.

The only thing I use is a FEASA LED analyzer. I'm in the electronics ATE (Automated Test Equipment) field, so I use them from time to time and we have a demo here at work. I tried it on the LED array and its not good for irradiance data, the fiber light pipes only receive data from one spot. Individual LED tests might be better if the data is usable. There are a couple pdf docs that explain the measuring and scales, but it would probably only be reliable in comparing the intensity of individual LEDs, not the irradiance of the whole array.

The FEASA retrieves information about the Colour, RGB, Hue, Saturation, CIE xy Chromaticity and relative intensity. They make 20 fiber analyzers so you could take 20 light readings in less than a second. Not sure if that would be of any use, I am not in the lighting industry so I don't know what valid tests I can perform with the FEASA to obtain usable grow data.

Yeah, figured you meant 740, hehe.

It was my plan to use white as an all-in-one PAR source for what the red and blue don't have. Pairing white with 660nm and 450nm makes sense. I might have to play with the 730nm far red also, but it seems there is controversy as to the usefulness of far red light past 660nm for photosynthesis.

If the whites don't emit enough green I may have to try adding a few to my next light. I have a small 21 Watt light I am playing with in a PC grow cab. I will try your suggestions after these finish flowering. I want to find that optimal ratio and light pattern I need for my array now that I know how to build them with high efficiency and thermal transfer. Maintaining the 25*C junction temp is critical to assure the output is intense and wavelength is still true. As the LEDs heat up, they give off less light and stray from their native wavelength. Something I'm sure only a few manufacturers pay attention to.