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LED grow lights experience?


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Old 08-30-2010, 07:55 PM
HydroACR HydroACR is offline
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Default LED grow lights experience?

Anyone here have any direct experience with led grow lights? The cost for them has been coming down, and I'm thinking of experimenting...

thanks!

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Old 08-31-2010, 01:14 PM
NorEastFla NorEastFla is offline
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Hey HydroACR, good to meetcha.

I started experimenting with LEDs myself about 6 months ago. I can share with you what I've discovered so far:

1. (This is the most important of all) They have a maximum distance, (Throw), that they can be used at with good results. I've found that regardless of led light type, 18 inches is the farthest you want to put the lights above your plant canopy.

Any further, and your plants will start stretching, (gaining internodal length), wildly. I tried 24 inches on some Super-Hot Peppers and the internodal length was truly awesome. Sometimes as long as 2 feet between nodes.

With the lights at 12" above the canopy, and the plants trained to maximize the canopy, the nodes tightened to only 1 inch. Quite a remarkable difference.

2. Here's one that has puzzled me to no end; I bought four 28 watt "Glow Panels". At 28 watts, they work perfectly. With the lights at 12" from the top of the canopy, I get growth that is comparable to a 400 watt hps at 24 inches.

The LED light manufacturers make lights that are up to about 300 watts per/panel now. The distance that you can use them does not change. the 300 watt LEDs *also* have to be kept no further than 18 inches from the plant canopy to be effective.

So, is the light has to stay within 18 inches of the canopy, and a 28 watt light works perfectly, then what would be gained by increasing the light to 300 watts? You would have arrived right back at the power usage that you had with standard HID lights!

Standard HID lights can be increased in power with the benefit of being able to raise them higher and gain square feet of canopy increases proportionally, thus increasing your plant yield per/additional watt.

It seems that increasing the power of LEDs will *NOT* increase anything proportionally. Perhaps an increase in fruit, but I'd have to see what increase would justify a Ten-Fold increase in power.

The growth I've had with the 28 watt LEDs is fantastic. My last crop of Super-Hots grew so fast, with so many blooms and peppers, that it blew away anything I've ever produced inside before.

My next experiment with them will be with "Tom-Thumb" lettuce. That type of lettuce only grows to a 5 inch diameter, so it will be a perfect growth crop for the 12" LED light distance. I'm going to cover the crop with my four lights, each covering 5 square feet of area, for a total of 20 square feet of lettuce.

I'm going to try a continuous harvest of lettuce by staggering the planting this 35-55 day plant at 50 plants within my 20 square feet of space with the four LEDs over them. It'll be interesting to see how well they do.

Good luck to you, HydroACR. Please post back here to let us all know how your experiments do.


EDIT: I have the seeds now for the Tom Thumb lettuce. Now to build the system. Lots of chores around my place. Being a home owner seems sometimes to be more of trying to keep the house from fallin on my head.

I'll start a thread when I get the Tom Thumb growing.

Last edited by NorEastFla; 09-06-2010 at 01:46 AM.
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Old 09-12-2010, 07:49 PM
HydroACR HydroACR is offline
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thanks for the response, I'll post up my progress and results....
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Old 10-14-2010, 02:56 PM
gabrick gabrick is offline
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I have used LED grow lights and not had as much success as HID lighting systems. I used the UFO LED system and I had to put the plants real close to the light to get results.
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Old 10-14-2010, 07:11 PM
NorEastFla NorEastFla is offline
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Quote:
Originally Posted by gabrick View Post
I have used LED grow lights and not had as much success as HID lighting systems. I used the UFO LED system and I had to put the plants real close to the light to get results.
That is how LED lights work. Even with the new 3 watt LEDs and hundreds of watts of power, they still only have a maximum throw of about 18 inches.

I've found that 4 to 6 inches is the best.
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Old 10-14-2010, 09:47 PM
halfway halfway is offline
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Quote:
Originally Posted by NorEastFla View Post
That is how LED lights work. Even with the new 3 watt LEDs and hundreds of watts of power, they still only have a maximum throw of about 18 inches.

I've found that 4 to 6 inches is the best.
Nor, have you had a chance to grow the lettuce?

Also, if the throw is so low with LED, how do you compensate for a 3 foot tall plant such as a tomato or habenero? I understand the lumens from HID can push deep into the foliage and I understood the higher wattage LEDs would do the same?? I also understood a 90w UFO could penetrate a deep plant.

Your question regarding 28w vs. 300w led is very interesting indeed.

I am debating the UFO 90 or 180 as I want to move towards tomatoes and peppers requiring red spectrum. The other choice is a $160 T5 H.O. 48" x 4 bulb system with red blue mix. Such mixed reviews and polarized opinions.....what a pain, LOL!
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Old 10-14-2010, 11:30 PM
NorEastFla NorEastFla is offline
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Quote:
Originally Posted by halfway View Post
Nor, have you had a chance to grow the lettuce?
No, I haven't. I got caught up in some home repair and I doubt I'll be starting any other plants this year.

I'll have my seedlings well established by spring and ready for my new outside hydro garden.

I'm building a 20' x 40' screened greenhouse with a Plexiglas roof. I have several systems I'm going to test against each other, plant for plant. The following year, I'll change my entire process to the most advantageous combination of systems as the results tell the winners.

I'm pretty stoked about it. It's going to be a really fun year.

When growing under LEDs, to adapt to a plant which is normally tall, you can use a screen with 2" holes and weave the plant. Using the right mix of nutrients would also be important.

When your entire screened area is full, just let the new growth go upward from each branching node that starts a really nice branch. Clip any you don't want to grow.

It sounds like a job, but it could be done with a radical amount of power savings per/crop.

I have an experiment I'm going to try this coming year. I'm going to make a spiral of heavy wire, about 24 inches across and train a pepper plant along it, allowing off shoots to grow at exact spacing while climbing the spiral. I think I can keep the plants within 18" while producing fruit.

If so, then LEDs would work inside using the same spacing. While not comparable to sunlight, the LEDs will just make the plant grow much slower than having sunlight.

I think by using LEDs on this spiral system, I'll get a bunch of peppers.

The 180s should give you nice tiny internodal length and lots of foliage. With the right mix of nutrients, you'd be on your way to a bunch of fruit.

The T5s would also work, but not with as tight of internodal length. More nodes, more fruit, if everything else is dialed in.

I love hydroponics. I might have 5 or six systems going next year. It's going to be a blast.

Inside, I plan to try to lettuce/LED growing.
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Old 10-15-2010, 08:32 AM
halfway halfway is offline
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Hope it's ok to post this blog. I got it from another forum and the author is a very decent guy with some great, informative posts. http://hydroponicworkshop.blogspot.com/ I post because some of his LED tests and photos are very interesting. Again, so much confusing info between the effectiveness of LED.

I understand some of the low wattage systems with individual LED in the .06w range would be very poor for penetrating canopy, but it seems any of the 1w, 2x, and now 3w individual LEDs should do well.

I also gather that China products are a "no-go" at this point because of warranties, workmanship etc.

The quest goes on.
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Old 10-15-2010, 12:27 PM
NorEastFla NorEastFla is offline
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The "GlowPanel45" LEDs I've been using are made in China.

They work fabulously.

With LEDs, the spectrum and how you use them makes all the difference.

If you prop them about 3 feet over your canopy, you get a bunch of half starved, lanky, plants with 36 inch internodal length.

If you keep them at no more than 6 inches over the canopy and they are of sufficient brightness for the type of plant you're growing, the plants will thrive, have super healthy foliage, tight internodal length and lots of fruit.

You should see some of the attempts I've seen. "Scarecrow" plants that looked like they were begging to be shot at dawn.

The best I've ever seen were a very short cherry tomato plant that was bushed out beautifully and had two pints of cherry tomatoes on it all year.

The guy was growing it on his bar with LEDs. The LEDs weren't in the pics and I don't recall what brand or size they were, but he proved it could be done wonderfully.
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  #10  
Old 10-22-2010, 08:38 PM
EarlyPan EarlyPan is offline
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Default LED lighting

Regarding growing under LED's it's important to remember that with light, light of any type, the intensity on a surface varies inversely with the square of the distance. That means that if a lamp gives you a given number of lumens on a leaf at a distance of one foot and you double the distance to two feet the lumens will decrease by a factor of four. It's also difficult to compare light of different lamps, even two different color LED's, because of difference is spectrums.
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Old 10-22-2010, 09:51 PM
halfway halfway is offline
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I know NorEastFla has posted some of this, but I'd like to expand it a bit.

Misleading or deceptive advertising really clouds the basics needing when comparing costs, country of origin, lifespan, customer support etc.

USA vs. China/Asian companies?

Please post results of growth. company and the price you paid if you don't mind. UFOs at 90w, 180w, 120w with 40 3w lights???

Panel vs. UFO?

I know I'm asking a lot, but I think this is the system that fits my needs, I just need some help with the questions above and have scanned all the posts on this board. The other option is a 4x48 T5 HO or VHO with both red and green. Price is $159, but requires new bulbs each year.


Thanks in advance.
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Old 10-22-2010, 11:26 PM
NorEastFla NorEastFla is offline
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Quote:
Originally Posted by EarlyPan View Post
Regarding growing under LED's it's important to remember that with light, light of any type, the intensity on a surface varies inversely with the square of the distance. That means that if a lamp gives you a given number of lumens on a leaf at a distance of one foot and you double the distance to two feet the lumens will decrease by a factor of four. It's also difficult to compare light of different lamps, even two different color LED's, because of difference is spectrums.
The inverse rule applies within the lights normal throw. LEDs have such a short throw at all that moving them beyond about 6 inches is pointless for plant growth unless for some reason you *want* plants with nodes about 3 feet apart...hehe

It would be like using an HID eight feet from the plant. Sure, the plant may survive, but it would be a very sparse plant with practically no growth.
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  #13  
Old 01-01-2011, 09:55 PM
mchale mchale is offline
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Thanks for this information. I was recently using HPS grow lights but interested in the advantages of LED grow lights.
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  #14  
Old 05-09-2013, 10:10 AM
torch1990 torch1990 is offline
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Default led grow llight experience

I have a lab which used to test plants growing with led grow lights. and all that lights i bought directly from one Chinese factory last year.

the light is awesome . but need time to test a satisfying result .
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Old 05-09-2013, 10:13 AM
torch1990 torch1990 is offline
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Default led grow llight experience

I have a lab which used to test some plants with led grow lights . all the lights i bought from one factory last year. the light it is awesome . but i think need time to test a satisfying result.

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