Lagniappe

If I were to use a mover, it would be to get uniform growth in large groups of the same plant. I would still not expand the grow area more than 1' or so beyond the rating, so it's best to just use more lights.(IMO)

Richard

When I do the math:

Suppose you want 1000 Watts. The cost of 1000Watt bulb + fixture + light rail is greater than 20 x 50 Watt bulbs + 5 fixtures. The fixed lights cost less to operate, and the plants have continuous light intensity.

__________________
Back in business at plantsthatproduce.com

natej740

Are the LED grow lights any good. I saw some on EBAY at a decent price. They had red and green LED's in them.

Richard

They work, but calculate the cost per watt.

__________________
Back in business at plantsthatproduce.com

natej740

The watts are low because it's an LED. Usually the light is way more intense from a LED than a regular bulb I was just wandering if they work for growing plants. I don't want a 1000W bulb electric bill...lol. I think the total wattage was like 13.8 watts and had like 225 LED's for like $26.95 buy it now price

Abnshrek

If they(LED Growlights) do work just remember since its so darn cold (alot of places) the heat you'd get from the high wattage bulbs is no longer there, heater is left to compensate.

__________________


I'm a Nannerhead :^)

Abnshrek

I did learn something recently I'd like to share.. Many of us aren't using a 220V fixture which self equalizes 110/120vac doesn't.. Mean if your running a mulitude of 100 watt bulbs off the same breaker you bill is going to be higher than if you ran the same multitude of lights on 3 breakers... thus equalizing the load over a number of breakers and reducing your amp draw.. :^) Ok say I have 6 x 200 watt lights on one breaker the draw is 1200 watts where as if I had it spread across 6 breakers my draw rate would only be 200. big difference..

__________________


I'm a Nannerhead :^)

Richard

The efficiency of the LED's is no better than any other choice, and less than some. It is incorrect to think that the LED's are more intense than an incandescent.

Divide the cost by the number of watts and then compare to other lighting choices.

__________________
Back in business at plantsthatproduce.com

OrganicBananac

Green spectrum?
The reason we see plants as green is because plants do not use this spectrum and reflect it back, hence why we see the color. Be very leery of a "green grow light".... trust me Many ppl use green LED lights to enter plant environments and NOT disrupt the photoperiod...
Maybe look at the specific spectrum of light each diode (LED=light emitting diode) is rated for and compare it with the studies of spectrums of light that plants absorb. This is where you will be able to separate the "good" from the "bad" lights, and unscrupulous companies. LED's are gaining momentum, but just do the homework and be a wise consumer before anyone spends 300+ on a fancy new rave light
Best of luck and have fun.

__________________
"You gon sit at my table Judas!!!!!"-Kat Williams

Richard

Excellent advice!

The output light spectrum should roughly match this diagram:



You'll find more information here: Chlorophyll - Wikipedia, the free encyclopedia

__________________
Back in business at plantsthatproduce.com

natej740

I'm sorry it was red and blue LED's......Also Richard you say an LED is not as intense as a incandecent bulb??? Have you ever seen an LED flashlight compared to a regular flashlight they are 4x (maybe more) brighter...

natej740

I'm sorry it was red and blue LED's......Also Richard you say an LED is not as intense as a incandecent bulb??? Have you ever seen an LED flashlight compared to a regular flashlight they are 4x (maybe more) brighter...

Richard

It's the amount of energy and the spectrum it is in that counts. LED's are about 90% to 95% efficient, so a 14 Watt LED module emits about 13 Watts. Likewise, a 54 Watt T5(HO) fluorescent bulb emits about 48 Watts.

Now to compare the purchase cost per Watt:
$8 for a 54-Watt T5HO --> about 15 cents per Watt.
$35 for a 13.8 Watt LED module --> about $2.54 per Watt.

__________________
Back in business at plantsthatproduce.com

wordwiz

I have a couple of small banana plants under 14 watt Red/Blue LED panels and they are doing better than one in the greenhouse.

Last year, I used them quite a bit for tomato and pepper seedlings and comparing initial cost, cost to operate, expected lifetime and the result, they were better than CFL bulbs and probably better than HIDs. But, they do not cover much area - not much more than a square foot per panel.

In another forum, a guy got a 300 watt LED from livingapartment.com.au and was going to try to grow peppers to fruit. He was okay but hardly thrilled with the results, especially given the $1300 cost.

An interesting note: if you place a red/blue panel too close to the plant, it will not burn the leaves, but it will cause the seedling to bend toward a specific bulb - I'm presuming a blue one.

Mike

Richard

What factors do you attribute to this?

__________________
Back in business at plantsthatproduce.com

OrganicBananac

LED's also do not have the spread that regular bulbs do, they only work when directly pointed at what you want illuminated.(Not in the sense they don't turn on...) This is a serious factor to consider, and also the reason that LED's have had such a slow start overtaking cfl's(compact flourecent lights), the quality of illumination depends on color of the light(spectrum) and the spread, the same factors to consider when looking at them for use with plants.

__________________
"You gon sit at my table Judas!!!!!"-Kat Williams

JCDerrick

For what it's worth, my 2 cents. Like Lagniappe I use two fixed 1000W MH lights in my garage to keep my vast variety of tropicals alive. It's worked for the last three years. It's not perfect, but it's worked very well for me.

I have both reasons to like and dislike MH bulbs, but the pros outweigh the cons in my opinion.

PROS
Excellent light source with a variety of bulbs
Decent grow area
Lights produce heat, keeps grow space warmer in winter
Most plants don't stretch

CONS
Cost (bulbs, ballasts, etc)
Bulbs must be replaced every other year**
Must be a certain height above plants to avoid burning them
Select few plants (some bananas too) stretch

**The bulbs don't HAVE to be replaced, but I've read multiple places that they loose their ability to provide the same energy to the plants (lumens maybe?) after a year of continuous use at 14 hours a day; but will continue to use the same amount of energy despite providing lower quality light. I figure that's every other year for me since I run mine about 6-months a year.

__________________
Malama 'Aina



Normal Jan. Low: 34°F, Normal Jul High: 92°F
Coldest: 16-20°F, Warmest: 98-103°F
Annual Precip: 48 inches

wordwiz

Richard,

I would have to say the lights as all plants get about the same amount of sun. But that would make sense. It doesn't mean LEDs are better than CFLs or HIDs. The plants were about 7" tall when transplanted in early December and it will be the middle of May before I can move them outside, so I was not that interested in growing them as tall as possible - I would hate to have to carry two six-foot banana trees down my stairs!

As OrganicBanana says, LEDs have next to no spread - a 12" panel stretches to cover 14" but one is large enough for a plant at this stage. I also have a 54 watt panel I can use but again, I'm just trying to get them to a decent size - maybe 3' max.

Mike

Richard

So basically, the temperatures and everything else has been the same in your greenhouse as it is indoors, and the LED vs. the sun are the only difference?

__________________
Back in business at plantsthatproduce.com

wordwiz

Duh, no, regarding the temps. My upstairs room does not go from 54 to 92 in one day! The room tends to stay between 65-80, depending on the amount and intensity of sunlight. Overall, the places stay about the same, though the GH gets cooler of a night and on some days, much warmer for 6-8 hours. The humidity in the GH is much higher than upstairs; what effect that has I don't have a clue!

Seriously, the more energy, in the form of light, a plant receives, the more it would be expected to grow, if conditions are close to the same. The cooler night time temps in the GH may have a tiny bit of difference, but I don't think that much.

If I was take two identical plants, put them in the GH, leave one to get just natural light and have a LED light over the top of the other, I would expect the latter to do noticeably better.

Mike