Seed starting & grow lights

I've been reading about LED grow lights and am curious if anyone has opinions about them vs fluorescents for seed starting.

Any advice for a first time seed starter?

Your choice.  I have been using the same sets of 4' T5 fluorescent shop lights since 2014.  The lights are "cool" and can be placed right above the starts.

sanderson wrote:Your choice.

+1

I am using 48" LED GroLights that have been in use for years. I bought these bulbs when the old Fluorescent tubes started burning out, and decided on them primarily because they run cooler and use less electricity - 18W vs 40W.   I had to modify the shop lights to take out the old ballast, though, since the LED's don't need them.

I have been using the same T 12s for years, they do a great job with nothing leggy but you gotta keep ‘em close to the seedlings.

Thanks, everyone.  I've been more inclined to go with fluorescent lights because they are more tried-and-true and initially cheaper.  Not sure yet, though.

Do you think the spectrum of the light matters?  I've read that some lights provide different spectrums.  Do fluorescents provide full spectrum light?  Is that important?  Does heat output matter at all to the plants?  I read that it can.

What about for microgreens and wheatgrass?  I'd like to try my hand at those, as well.

goodtogrow wrote:Do you think the spectrum of the light matters?  I've read that some lights provide different spectrums.

Yes, there are different spectrums for leafy growth, for fruit production, for flowering, etc.  Many grow lights, like the LED ones I bought, include a full spectrum range.

Do fluorescents provide full spectrum light?  Is that important?

Depends on the design of the bulb. There are also High Output tubes which provide more intense light. Check out this article for some good information which fluorescent light is best for plant growth.

https://university.upstartfarmers.com/blog/choose-fluorescent-grow-lights

Does heat output matter at all to the plants?  I read that it can.

Yes, if the bulb is putting out heat it will burn the leaves if the bulb is too close to the plant. I keep the LED grow lights about 3" above the plants. When I had fluorescent grow lights, I had to keep them just a little higher.

Thank you, OhioGardener.

Well, maybe I'll look into LEDs, then...

Sure is a lot to learn with these things, though...  As for Wattage, how does this correlate to actual light energy output?  You mentioned 18W vs 40W - does wattage equal light energy output (like with incandescent bulbs, for example), or is it different with LEDs?  I recall reading somewhere that PAR is a better metric for this?

And do plants need a certain amount of light output minimum?  Are microgreens / wheatgrass different or about the same in terms of their light needs as vegetable seedlings?

Some people say "just get an old shop light" and then I also read that "you should get the right thing that works for you"...  Trouble is I keep finding dozens and dozens of different lighting options from $40 to $2000+ and I'm still not sure what to go with.

Ideally, I'd like to get a 4' long, 20" deep, 3-tier shelf where I can grow microgreens and hang the lights above them.  I also want to use this for starting seedlings for our SFG.  I'm thinking full spectrum LED lights, relatively cheap.  To start with, I just want to get one or two lights (for one or two shelves).

Should I just go for something like a SunBlaster one?
https://www.sunblasterlighting.com/our-products/grow-lighting/led-strip-lights/
or
https://www.amazon.ca/SunBlaster-0900302-Nanotech-Reflector-Medium/dp/B0748CH4B9

There's also these "prismatic" ones that focus the light better?
https://www.sunblasterlighting.com/our-products/
https://www.amazon.ca/s?k=SunBlaster+led+Prismatic
https://www.amazon.ca/SunBlaster-0900703-Strip-Light-Medium/dp/B0748D3JV9

goodtogrow wrote:Sure is a lot to learn with these things, though...  As for Wattage, how does this correlate to actual light energy output?  You mentioned 18W vs 40W - does wattage equal light energy output (like with incandescent bulbs, for example), or is it different with LEDs? 

The 18S vs 40W is power consumption, not light output.  The important thing in grow lights is the Kelvins (K) rating.  The closer to 6500K (natural light) the better. And, of course, the color spectrum depending on what you will using them for.

You can spend a lot of money on lights, but it really isn't necessary. I bought 48" 4-tube shop lights from Lowe's, then ordered 48" LED grow light tubes on-line to put into the shop lights. The tubes I bought required me to by-pass the ballast, which took about 10 minutes per light fixture.  Unfortunately I don't remember who I bought the tubes from, and it has been so many years they may not even be in business now.

Thanks, that helps shed some light (sorry).   :) 

Then I found this one:
https://www.amazon.com/Exlenvce-Spectrum-Fixtures-Function-Triple-Chips/dp/B07QY16YRD

But it seems quite different from the SunBlaster ones, namely the light spectrum.  Looks like overkill for me.

It seems like I only really need the "veg" spectrum for starting seeds (blue light?), not the full spectrum of light, after all, I think?  Is that veg light spectrum sufficient for growing lettuce and spinach, as well?

Maybe all I need is this one (fluorescent):
https://www.amazon.ca/SunBlaster-0900304-Light-NanoTech-Reflector/dp/B07489KMLP
or this one (LED):
https://www.amazon.ca/SunBlaster-0900704-Strip-Light-6400K/dp/B0748CP66H

Reflectors that are white underneath are better than black.  Two-wing reflectors are better than one-wing.

How many lights you shell out for depends on how many seedlings you want to start indoors.  When I started flowers in addition to the veggies, I had 8 10x20 trays under four (4) 48" shop lights.

Sanderson, they're only black on the top, white on the bottom, from what I can tell.  I would hope so, at least.

I think I'm going to go with a couple of these (2' ea):
https://www.amazon.ca/Prism-LED-HO-Strip-Light-6400K/dp/B08DDF4ZNT (C$60)
That way I can arrange them either side-by-side or end-to-end.
They are "full spectrum" and have pretty good light output, apparently.
More info here: https://www.sunblasterlighting.com/our-products/new-prismatic-led/

I've read that plants, including seedlings, do benefit from full spectrum light.  Some research suggests that blue light can also increase the levels of antioxidants in microgreens:
https://pubmed.ncbi.nlm.nih.gov/28317756/
And red and green light can boost antioxidant levels in microgreens, as well:
https://pubmed.ncbi.nlm.nih.gov/32129889/

It appears that the red spectrum benefits plants more than just in the flowering stage, too:
https://gpnmag.com/article/red-light-and-plant-growth/
Encouraging stem, leaf, and general vegetative growth - but most commonly, tall growth, stretching of leaves and flowers.

And apparently green light even contributes to essentials aspects of plant growth, when it used to be thought seedlings and many plants didn't need green light:
https://academic.oup.com/jxb/article/68/9/2099/3857754

Oh well, hopefully this helps someone other than myself.  Just thought I'd share what I've learned.  Still learnin'!  And thanks again for the help. 

goodtogrow wrote:. . . I think I'm going to go with a couple of these (2' ea):
https://www.amazon.ca/Prism-LED-HO-Strip-Light-6400K/dp/B08DDF4ZNT (C$60)
That way I can arrange them either side-by-side or end-to-end.
They are "full spectrum" and have pretty good light output, apparently.
More info here: https://www.sunblasterlighting.com/our-products/new-prismatic-led/

What is the spread (coverage)?  Will they cover a 10"x20" tray full of seedlings?

I've read that plants, including seedlings, do benefit from full spectrum light.  Some research suggests that blue light can also increase the levels of antioxidants in microgreens:

It appears that the red spectrum benefits plants more than just in the flowering stage, too:

And apparently green light even contributes to essentials aspects of plant growth, when it used to be thought seedlings and many plants didn't need green light

Oh well, hopefully this helps someone other than myself.  Just thought I'd share what I've learned.  Still learnin'!  And thanks again for the help. 

Growing plants indoors would require better lighting than what is good enough for starting seedlings indoors.  Our seedlings will eventually be moved out doors where the good old sun will provide all the different spectrums needed for mature plants.  Whether to go with cheap T5 fluorescent shop lights or the full spectrum lights is a personal choice.

Another thing to consider is whether one can tolerate the weird lighting indoors.  

I finally found this old photo from Quiltbea!!  Grow stations don't have to be fancy!  She added old VHS tapes, books, bricks, etc., to vary the height a as the different plants grew.

Sanderson wrote:What is the spread (coverage)?  Will they cover a 10"x20" tray full of seedlings?

Not sure what the spread is, but I think they should cover that much.  All I know is what I read on that link I shared.  They have a "90 degree angle", so I guess maybe about 1-2 feet at around 10 inches above the shelf?  Just a guess, though.

Growing plants indoors would require better lighting than what is good enough for starting seedlings indoors.  Our seedlings will eventually be moved out doors where the good old sun will provide all the different spectrums needed for mature plants.  Whether to go with cheap T5 fluorescent shop lights or the full spectrum lights is a personal choice.

True enough, but why not kick-start seedlings with more health?  What I'm finding out is that by using full-spectrum light for seedlings, it starts them out as inherently healthier plants at very early stages of their life, which is proven by the higher antioxidant levels, etc.  I do believe that is not only good for people eating them, but that it will lead to healthier plants, in a shorter time frame.  Perhaps it will even help plants to yield more and higher quality fruit.  I'll have to test this theory out one of these years, I suppose.  Maybe I'm totally wrong, who knows, but I personally do think there's something to it.  But this is beyond my capacity to test out in a lab, and testing anything in the garden takes awhile, I guess. 


Those photos from QuiltBea are great - hopefully nothing caught on fire!