Review: LED lights

So this year I had a some extra cash, and the metal halide light I had been using for lo, these many years was due for a new bulb. The time was ripe for a radical change.

I'd always been unhappy with the amount of power this used and the dangerously enormous amount of waste heat it created. Due to all the heat, my tomato plants generally grew too tall too fast and all the plants were always prone to wilting and water stress.

My plant set up is a three-sided 'light box' lined with mylar and draped with a half-length mylar sheet on the open end. I use an oscillating fan blowing in on the plants (and had another on top of the light trying to keep it cool). I typically grow up to

40 plants in re-used 32-ounce yogurt tubs (arranged in staggered rows for maximum density).

This year I decided to go high-tech, and did a bit of research and some fairly serious spending.

My set up this year used two LED light fixtures. The main light source was a LightBlaze 400 LED grow light roughly centered in my light box. Behind it I hung a second LED light fixture, a GlowPanel 45.

I still used the oscillating fan blowing into the box, but as everthing was running so much cooler, I laid another sheet of mylar across most of the front of the box.

I'd have to say the whole thing was a sucess. My tomato plants are much shorter and more robust looking, as are the peppers and eggplants.

It was strange how black the plants look under the LED lights, but that is a sign that most of the light was actually being absorbed by the leaves and very little was being reflected, which is a good thing.

The weirdest thing to get used to was how odd *the rest of the world* looked after fussing over the plants a bit; everything took on a distinctly green after-glow.

The LightBlaze 400 puts out more light than the GlowPanel 45. and is easier to hang and adjust, but I think if you put together several GlowPanel 45 grow lights you could get the same results.

LightBlaze 400:

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Systems GlowPanel 45: Available from Amazon.com and other sources.

Reply to
Pat Kiewicz
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Very interesting. I will keep it in mind.

This year I got a late start on my tomatoes. I started the bulk of mine on 3/15 and a few more late arriving seeds on 3/27. I started the first ones in the house with grow lights and the second ones in the greenhouse. The first ones got leggy very fast and I moved them to the greenhouse as soon as most of them germinated. They all went outside as soon as it was warm enough. I set out the first block on

5/10 and the second one yesterday. The ones that I started in the greenhouse look much better. Think I will bite the bullet and heat the greenhouse next year and keep all of the tomatoes in it and not try to start too early. Maybe slower germination but better looking plants later.

I am betting that the later starting plants will be more successful that the others. I remember reading somewhere that a healthy plant resists insects better. I am guessing they also resist diseases better.

Reply to
The Cook

Oh, yes, I agree that it doesn't pay to start too soon. Better to wait, and have plants that are smaller but unstressed and never checked in their growth. Which is one reason I'm happy with the LED lights, as the plants avoid all the heat stress from the metal-halide lamp that I used to use.

I started my plants on April 9 in Jiffy-9 peat pellets, transplanted them into the 32-oz yogurt tubs on April 25 and took the tomato plants outside for the first time on May 19, when our weather finally broke mild again. After a few days of hardening off they may get transplanted out. (Each year this depends on the way the weather trends at the end of May.)

The peppers and eggplants won't be going out quite yet but they can use the extra room under the lights now that the tomatoes are outdoors.

Reply to
Pat Kiewicz

Then there is T5HO florescent lighting, which I used this year, and am very happy with.

4 Light T5 High Output Fluorescent High Bay Fixture

Features:

(4) 54W T5 High Output Lamps

5-Year Ballast Warranty

Specs:

20,000 Lumen Output 83 Lumens per Watt 95% Lumen Maintenance 20,000 - 30,000 Hour Lamp Life 98.7% Fixture Efficiency 239 Input Watts 120-277V 50/60Hz Programmed Start Ballast

-20? F(-29? C) Min. Start Temp

This for $119 vs $627 (LightBlaze 400 LED Grow Light)

Reply to
Billy

I went with this Jump start system this year. Works!

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Reply to
Bill who putters

I almost bought one of those this year, but money is tight so I just used my F32T8 lamps. (I also have a 400W HPS floodlight that works pretty good, but I didn't use it)

Did you get one with a polished reflector, or bright white? (I would probably get white to avoid hot spots)

Bob

Reply to
zxcvbob

I wonder if a person who was handy could add a row of these red LEDs to an existing 2x4' fluorescent "troffer" fixture? Just need to red ones because fluorescents give off plenty of blue already.

They could be powered by an old laptop power supply (typically < 20V and maybe 90W)

I may need to ask about this in the sci.engr.lighting froup.

Bob

Reply to
zxcvbob

By chance I got white. What do you mean by "hot spots". Irregularities that focus the light onto spots? This looks like a regular shop light with 4 florescent tubes. For lack of space, when I need to rotate trays in and out of the light, the trays that are out will often get put on top of the fixture, and there, they suck up a little heat as well. A year ago these were about $200. In Jan. 2010, they were $149. Now they are $119.

There's a comparison between florescent and L.E.D. at

Reply to
Billy

That's also covered at

I had a 2 tube T5HO that I use for germination, in conjunction with a heating pad, but it was barely sufficient to carry the plants through the last cold month of winter and into early spring, when the plants could go outside. This year I was able to put them under descent light after they completed germination, and the plants were much stronger when they went into the garden. I still have a few things to learn and a few bugs to work, but over all, I am very pleased with the results.

Now if the freakin' rain would stop. We've had 4 days of rain already this month (very unusual), and rain is predicted for tomorrow, and next Tue., Wed., & Thur. Grrrrrrrrrrrr

Reply to
Billy

Yes, that's exactly what I meant. Not sure if it's a real problem or an imaginary one. IIRC, the white actually has a higher reflectivity than the polished aluminum version.

They were $160+ locally last time I checked, but that was probably November or December 2009.

Bob

Reply to
zxcvbob

Well today we have 85 F. and a mild breeze under full sun. However last Friday I spent $500 to have my septic pumped and never before the lines reamed. I thought my arms were using plungers in my sleep. Should have known something was amiss when all drains acted up over time. Put out this fire and another would arise. Usually the septic trap says check me out not this time. March rains and the rise of water table are even getting the county declared a disaster area. Sort of knew thing were off when my brother and dad's house flooded from the basement floor. I was lucky to have a few more feet elevation but not exempt from rising water this ground water played on the field drain.

Fingers crossed things normalize a bit for everyone.

Reply to
Bill who putters

Why not just get 3000° K fluorescent lights?

Reply to
Billy

That's what I'm using. Two F32T8 lamps per 2x4' fixture, on a ballast that overdrives them about 20%. Bare buls with no diffuser. It work surprisingly well considering the wattage. But there's a lot of unused space down the middle where I could put a strip of LEDs to augment the fluorescent.

Bob

Reply to
zxcvbob

Would that be cheaper than $119 + tax and shipping?

Reply to
Billy

Did you see that they have a 30000 lumen version for $149?

Bob

Reply to
zxcvbob

I don't know where you are going with this. How about (2) 20,000 lumen for $238 vs. $627?

Reply to
Billy

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