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Subject:  led grow light

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ThePumking

kennedy New york

New grower here. Wondering if anyone uses a led grow light for seedlings??

3/4/2018 8:03:35 AM

Farmer Brown (Chris Brown)

Zimmerman, Minnesota

Yes

3/4/2018 12:09:23 PM

bnot

Oak Grove, Mn

yes, they will work great for seedlings. If your light has the switch for veg-bloom put it on veg. This will give you mainly blue light spectrum which seedlings love. Different LED's will put out different level of PAR light. You will have to learn how high to put the light above your plant. If they are stretching out, you need to be closer. The best thing about LED's...it is really hard to overheat the young seedlings.

3/4/2018 2:48:36 PM

ThePumking

kennedy New york

Thanks. Light is off of amazon and is a 50w circlular light with only blue and red leds. Planting season is still a little ways away but planted a seed this morning on a heat mat just to try it out

3/4/2018 6:05:39 PM

Porkchop

Central NY

Post a link to the light...need good strong light for good strong starts...t5 lights are prolly your best bang for your buck..(I think Ron is selling them in his website now)...leds are good if you have a good light...mine covers about 3*3ft area...it was around 600.00...those little junky Chinese lights are not good...good luck!!

3/5/2018 8:32:58 AM

bnot

Oak Grove, Mn

50 watts is probably not big enough. It might be ok for one plant but you won't get a very wide footprint of usable light. To cover a 3 foot x 3 ft area like Porkchop said would take at least about a 300 watt high quality LED (actual wattage draw of 180 watts). I like excess light..I would probably put 600 watts of LED over that area.

3/5/2018 9:27:13 AM

pumpkinpal2

Syracuse, NY

i have two 4-foot X 2 fluorescent tubes-each, shop-style lighting fixtures, each with one aquarium tube and one sunlight tube for a mix of the two from each; they're
side-by-side and i line the plants up under them from the middle outward as they become available. the lights are suspended from each end by cotton/nylon clothesline cord running through screweyes screwed just-right into the rafters above. the two cords from each end are tied together at many points a few inches apart and hitched-over two adjacent drywall screws and i can raise/lower them as-needed from any level to any level. each tube is 40 watts each. the closer your lights are to the leaves, the less leggy they will become - period. 12-on, 12-off is loosely just like outdoors, where you WANT them to become leggy and grow quickly, but fully-on 27/7 and even ZERO inches above them is my weigh to go. in MY case, the plants are often BETWEEN the tubes, and it is NEVER a problem;
man, i am having SUCH a flashahead to planting day!

3/5/2018 11:17:18 AM

pumpkinpal2

Syracuse, NY

correction 1 - fully-on 24/7
correction 2 - the leaves are often between the tubes
...and they gave me a license to drive.

3/5/2018 11:23:30 AM

Zeke

Team Canuckle Heads

Check out "Rising Sun" light hangers. I paid $20 for the pair. Work great.

3/5/2018 1:09:32 PM

Orangeneck (Team HAMMER)

Eastern Pennsylvania

I just put some pics of my new led setup in my diary. I hope that is some help for your ideas.

3/5/2018 11:45:03 PM

pumpkinpal2

Syracuse, NY

Very impressive and innovative! Great about the reflective paper; had not thought much about side- and 'bottom-lighting'; hmmm...
Rather enjoy the COLORS the COLORS of the assembly. Even all closed-up, though, it still looks like you're 'up to something', lol---don't worry, we'll all vouch for you---eg

3/6/2018 12:08:36 AM

bnot

Oak Grove, Mn

We are going to have to get you into the winter grow orangeneck. You have enough LED wattage there to grow a tomato plant to maturity. The colors are pretty but I suggest having a white source close to evaluate leaf quality.Purple LED's hide some symptoms such as chlorosis between leaf veins. Two weekends ago, I saw what will probably be the next step in the evolution of LED's..it is a white LED grow light. I measured the PAR numbers from it and determined it was still slightly less useable light(for photosynthesis) than my blue-red 300 watt but would be so much easier to grow under. At $750 for 300 watts the price needs to come down before I buy.

3/6/2018 3:26:41 AM

Big T Hoff

Hadley Ny

Mirrors work for side and bottom lighting also.

3/6/2018 7:28:21 AM

Orangeneck (Team HAMMER)

Eastern Pennsylvania

I think I’d have to prune very aggressively to get a mature tomato as my headroom is only about 30 inches.

I thought avoiding white/ full spectrum light is desired because many wavelengths are not usable by the plant at all, therefore it is wasted energy?

Maybe I could train a tomato plant to grow somewhat horizontally once it gets abot 12 inches tall?

Yep it looks like a marijuana grow but it really is closed up for heat since the ambient temp in my subterranean basement is 62 F. And also so that I don’t kick the plants or cover them with sawdust while working. But once it is legal I guess I’ll be ready :-)

3/6/2018 10:57:27 AM

bnot

Oak Grove, Mn

It is true that white light LED's are not as energy efficient as LED's for photosynthesis as a mixture of blue (400-500nm) and red (600-700nm). Some sources say that 40% of the electrical energy is lost with white lights that include much of the green spectrum (500-600nm) since it is not used for photosynthesis. There is the alternative argument that plants can utilize green light to some degree. Accessory pigments such as Carotene and Xanthophyll aid in the the photosynthetic process and absorb green light to some degree. There is also the discussion of Action spectrum and Absorption spectrums. The Action spectrum is the spectrum that causes light dependent reactions in plants. The Absorption spectrum is what is actually taken in by the chlorophyll. I have seen some studies that early seedlings may preform better under the Action spectrum (white light-blue green red) as compared to the Absorption spectrum (blue-red). This phase seems to be a short time. But for the most of the growers here, a few weeks of seeds starting is all they use the grow lights for.

Orangeneck..not going to buy the height limitation...I see some nice tools there...going to be waiting for you to build a really fancy grow cabinet for the winter grow :)

3/6/2018 5:04:53 PM

bnot

Oak Grove, Mn

The problem with reflective substances to increase bottom and side-lighting comes from what is known as the Inverse-Square Law. Sunlight measured at 8 ft above ground is going to give you about the same PAR(photosynthetically active radiation) as you would measure at ground level. This is the advantage of sun over indoor grows. The source of the light is so far away that the amount diminishing by distance is so much less. As compared to a grow light..a few inches from the bulb it might have very high PAR numbers...those number drop quickly as you move farther away from the bulb. On a 6 inch plant..it won't make a difference. But if you take a 3 foot plant (winter grow) and then try to bounce the light from 3.5 feet above off from a sidewall that is 1 foot from the plant you are going to be dropping into numbers that won't make a difference...that is a 4.5 foot loss of intensity. What humans perceive as bright..and what plants need to eat is way different. I have a $500 PAR meter that I have checked grow lights, sunlight, room lighting etc. My suggestion if you are just using the grow lights for early starts...get a reasonable grow light, place it at a height where you are not cooking the plants from heat and let them go. I could give you the uMols where I think that plants respond to the best..but unless you have the meter...it won't help you.

3/6/2018 5:30:37 PM

ThePumking

kennedy New york

Orangeneck your getting 85 degrees from one seedling heat mat? i got mine from lowes but im not sure how hot it gets

3/6/2018 8:18:18 PM

Orangeneck (Team HAMMER)

Eastern Pennsylvania

Yes but it is a big one 20 x 48 inches. If you are using full spectrum lights they will also warm the area.

3/6/2018 9:08:49 PM

baitman

Central Illinois

emergency blankets are Mylar which I think is the best, thicker is better,flat white paint is also very high, mirrors look bright but are the lesser of the three for reflecting light. Most fluorescent lights are gloss just to make them more attractive

3/7/2018 9:52:37 AM

North Shore Boyz

Mill Bay, British Columbia

Regular LED lights will not work and your seedlings will be leggy.

3/7/2018 11:41:36 AM

bnot

Oak Grove, Mn

What you are referring to North Shore are the household LED bulbs. I checked my household bulbs a few weeks ago. An Led replacing a 60 watt incandescant bulb registered 100 uMols about 2 inches from the bulb. Drop to 6 inches..it was down to about 25 uMols. My household LED spotlights were a bit better..2 inches from the bulb I was getting about 350-400 uMols but at 6 inches was getting about 80 uMols. I like to run my seedlings at about 400-500+ uMols of PAR. With my 300 watt LED grow lights I can get that number at 30 inches. If you are shopping online for LED grow lights...pay attention to number of spectrum bands that the light offers, it is a bonus if they will advertise their PAR number at certain heights and the footprint of the light. There is a difference in quality of individual bulbs..I think Cree is considered tops right now and there is a difference of what angle is in front of each bulb...common right now are 60 and 90 degree angles. As Porkchop said..there are some China Led grow lights out there that may look pretty but don't deliver the light. There are some other China lights out there that are very close to the top USA manufacturers. COB Led lights also might be worthwhile for consideration. Lots of factors to consider..original cost vs usable light output, wattage cost to operate etc. For most of the growers on this website, it is not that critical. I have met some 50,000 watt grow room operators...their decisions involve thousands of dollars.

3/7/2018 5:37:23 PM

Orangeneck (Team HAMMER)

Eastern Pennsylvania

Thanks bnot I will check if my brands have detailed specs. Also I have already begun the mental designing of my winter tomato grow box. Thanks

3/9/2018 9:21:15 AM

Total Posts: 22 Current Server Time: 3/28/2024 5:52:50 AM
 
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