Yes. If you want to use them for fruiting/harvesting fruit, they will need to be more powerful than the 14 watt panels one finds on e-bay.

Mike

Wordwiz, What type of LED system is needed instead of the 14 Watt panels on EBAY? Can I use 2 or 3 panels together to provide enough light for fruiting/harvesting fruit for Tomatoes or Peppers? Thanks for any advise.

Stimpy,

I suspect that for tomatoes and most peppers, you are going to need a panel that supplies at least 5,500 lux at the plant canopy. As much as I like LEDs, they are still a bit pricy. I'm using one for a huge Bhut Jolokia but it hasn't started blooming yet (these plants seem to take months to bloom). I'm also using a 105 watt CFL on some plants - a cuke, Green Sausage tom and a Red Delicious tom. The Delicious should start blooming in a couple of weeks.

While the costs for electricity are a bit higher (105 vs. 55 watts), the bulbs are way cheaper. I bought six 105 watters for $137 which included shipping.

Mike

I like those 105 watters, they're pretty handy. Not much heat, they go right into a regular light socket, and they really pound out lumens for a CFL.

Like wordwiz says, it's still pretty expensive to get LEDs good enough to really grow much. In most cases it's cheaper to buy a HID, the cooling hood for it, and a year's electricity.

where can one buy the 105 watters. I did a search with no luck. We have grow lights on our plants but they r not doing very good.
Thanks

http://www.1000bulbs.com/105-Watt-Compact-Fluorescent/

Mike

That's where I got mine. They send out mildly-annoying sales announcements via email every week or so, but it's not too bad.

Put a couple of those 105 watters together with some good quality nutes and you can grow just about anything.

FWIW: I have a 14 watt unit and it is pretty much use less. Have two 48 or 50 watt units and they seem to grow pretty good. One tomato has buds now. If you buy the larger unit make sure you buy from the fellow that has the one with an external 24 volt supply. I had all kinds of returns of the ones that have the built in supplies. Would up moving the PS to the out side because of heat. Those one foot square units are sure handy tho. Point the light where you want it.

What 105 watt bulb would you buy? the 4100 cool white, the 5000 full spectrum, or the 6500 day light?
I would tend to lean to the full spectrum.
Kenny

I use an LED growlight for seedlings it works out great.

Has anyone tried these (link) LED's?

Here is a link that might be useful: LED Grow LIghts

Those are 14 watt panels, not powerful enough for fruiting.

Mike

And way over priced.
Kenny

It is pricey... I did get this a couple weeks back http://shop.sunshine-systems.com/product.sc?productId=11

Its the grow spot. It works out great because its a decent amount of wattage concentrated on a smaller area. It works out great for sprouting stuff or focusing on a plant in a 5gal container or smaller. I would just blast the plants with CFLs from 1000bulbs.com. I have not did a scientific test but it seems to me the 15watt grow light sprouts better then using a single 42watt cfl.

colokid - You want the 6500K CFL. The others are crap comparatively. Only the very high color temp lights have strong enough blues for good vegetative growth. For flowering plants you'll probably want some 2300K CFLs too.

It depends a bit on the plant for what kind of color temperature mix you'll want, but with the CFLs you only want the two ends of the spectrum. The variation is just in the ratio of daylight and warm light bulbs.

Thanks garysgarden.
I have two 48 inch 40w cool white 4100k Hanging over 2 container. Have a 48w red/blue LED at each end. Tomatoes are 18 inch high and blooming, so I guess the LEDs are doing the red OK. Think I will give up the T12 unit and go to CFLs for more growth. Wound up with the T12 for 7 dollars with bulbs at the habitat store, so had to try it first. Might just pull the T12 bulbs and mount 2 twin light sockets in the same reflector. That would give me 4 bulbs in 4 foot.
Kenny

There's a lot of different ways to grow, no one's completely right or completely wrong. Well not usually completely wrong. Incandescents are totally wrong but you don't see many people doing that.

I see a lot of people using tube lights like the T12's for starting plants early for outdoor planting after the last frost, but I've also seen them for strictly indoor from seed to harvest growing too. It just depends on what works best for what you're doing and growing.

Thanks for the tips. I guess I'll forego growing with LED's for now, but I do intend to try a little experiment:

I just bought a red LED tail light for my bicycle at Harbor Freight for $5. I says it'll stay "on" for some ridiculous amount of time, so I intend to bathe part of the tomato family in red light for one season to see if it makes a difference. I have it on pretty good authority that tomatoes grow better in RED light.

Red is red, right? I'm hoping the "source" doesn't matter. I'll let everyone know when I get results.

Sounds interesting.

I think LEDs could make a useful contribution to an indoor grow cabinet but they're not quite ready to take over the task of lighting.

>> Red is red, right? Yes and no. Plants thrive under specific wavelengths. A lot of people believe 630 or 640 to 660 is the ultimate wavelength and some newer panels are combining them (with blue and even a couple of white bulbs).

Mike

According to Philips Lighting application guide for Horticultural Lighting, 675 nm is the peak for monochromatic efficiency. That means, of the monochromatic spectrums, red is the best. However I recommend a full spectrum, with a slight increase in the red (preferably at 675 nm).

If you're looking at 100w lights, why not consider the 100w CMH by GE? With e-ballast, socket fixture, and reflector, this goes for about $150. And it is full-spectrum.

I have used 14 watt LED pannel and the growth of the seedlings were subpar, albeit there was growth and the plants did not stretch, but when I put the plants under my t-8 500k daylight Fluoro's they sprung up fast. I like the t-8 2900 lumen daylight bulbs as they have one of the best effeciency out there 90 lumens per watt where as the 105 CFL at 6900 lumens is only 65 lumens per watt. not to say they are not good, but if you are looking for a balance between effeciency and power they are a good choice. But if you need to power alot of lumens in a small area the CFL is great

FWIW: I am doing a test of seeds. They are about 4 inches under a 14 watt LED panel. They are just starting true leaves. They are not leggy, but are not growing like I want. Seems to me to be very slow. Temp is at 76 degrees with heat mat. I once measured the power to a listed 14 watt unit and they only draw about 4 or 6 watts. I think they rate the LED unites by the max LED rating and not what they actually are doing. Same with my 48 watt units. About 15 watts true. I feel that the results from the LEDs are about what the actual wattage is, not what they advertise them at. In other words, consider the results about like what you would get with a 6 watt bulb. The 48 watt units do some good, but the 14 watt is pretty use less.
Kenny