Best Color Spectrum Light for Starting Seeds Indoor

[777thSunRay]

I get conflicting opinions online about the best color/spectrum of light to use for starting seeds indoors. A particular lamp set, with 150 led bulbs, has the following options:
Full Spectrum (100 red and 50 blue bulbs)
Full Spectrum White (120 white and 30 red bulbs)
Mixed Spectrum (60 yellow 60 red and 30 blue bulbs)
Red Blue Spectrum (100 red and 50 blue bulbs)
If it makes a difference, I will have the seedlings right by a window facing west and slightly south, unobstructed light after midmorning till sunset. I have the understanding this alone is not sufficient, correct? But I'm wondering if it would affect which lamp I should use. Please keep in mind this is only for seedlings. Any elucidation on this topic would be greatly appreciated!

 

[penumbra]

All this red, blue, yellow, white is not of much help, but if I had to pick one of the above I would pick the one with a lot of white light. Personally, I prefer T5 fluorescent in a 5500 to 6700 kelvin rating for seedlings over LED lights of dubious provenance.

 

[777thSunRay]

All this red, blue, yellow, white is not of much help, but if I had to pick one of the above I would pick the one with a lot of white light. Personally, I prefer T5 fluorescent in a 5500 to 6700 kelvin rating for seedlings over LED lights of dubious provenance.

Okay, this is good to know. The led sellers do claim that Kelvin range in their white bulbs. What is the advantage of fluorescent over led? I don’t doubt it, just curious as to why. Is there a brand you would recommend? Thanks

 

[Glaucus]

Full Spectrum White (120 white and 30 red bulbs)

This one by far.
The others are not even worth the money or effort because they have zero white LEDS.

Full Spectrum (100 red and 50 blue bulbs) is NOT full spectrum, at all.

One can debate about how warm or cold the white LEDs should be. And about how many red LEDs to add.
Usually, what is best is a mix of cool and warm white LEDS mixed in with some reds.
But there is some debate to be made that you want the spectrum to be higher on blue light at some point in the growth cycle, because this will produce really compact plants and shorten internodes by a lot. Which can have several advantages, both bonsai and non-bonsai related.
But initially, I would say it is pretty good if a seedling has some elongated growth.

The advantage of T5 is that they are very well suited for vertical growing when you have shelves. Or that they are cheaper to buy initially. Or that they produce some more heat which might be desired in an otherwise unheated room. LEDs will not be worth the money if you use the light for 12 hours a day in February to April for 2 to 3 years. If you are going to spend more on electricity, for example because you know that the coming 10 years you will use it from December until April, and run it 16 hours a day, then the cost of the light is going to be smaller than the cost of the electricity. And then LEDs become cheaper.

Also, the diversity of products among LED grow lights now is pretty high. The traditional light bulbs that can compete with LED grow lights are 1000 watt HID (HPS/MH) lamps. Few people would want to run 1000 watts worth of lighting indoors. Of course the other alternative are actual fluorescent like T5.
Of course T5 and T8 are size formats, so you can also buy LED loaded tubes now.

There is no reason to buy 'LEDs of dubious performance'. There are tons of Youtube channels that test LED panels of major manufacturers using high end light intensity meters that specifically measure the intensity of light that plants would use for photosynthesis (as opposed to either photon or energy flux or apparent brightness).
While there are tons of dubious LEDs available on sites like Amazon or your local Home Depot or Walmart, it is not so easy to buy a independently reviewed T5 fluorescent bulb, because people don't really bother. Also, LEDs seem to be a fundamentally more reliable technology. One issue would be thought that individual diodes on a LED panel may break. So over the years (or decades?), you will slowly lose more and more of them. But for a fluorescent, one day it will just stop working and you know you need to replace it.

I can give recommendations if you specify how large your area will be and how long you plan to grow them indoors.

 

[777thSunRay]

This one by far.
The others are not even worth the money or effort because they have zero white LEDS.

Full Spectrum (100 red and 50 blue bulbs) is NOT full spectrum, at all.

One can debate about how warm or cold the white LEDs should be. And about how many red LEDs to add.
Usually, what is best is a mix of cool and warm white LEDS mixed in with some reds.
But there is some debate to be made that you want the spectrum to be higher on blue light at some point in the growth cycle, because this will produce really compact plants and shorten internodes by a lot. Which can have several advantages, both bonsai and non-bonsai related.
But initially, I would say it is pretty good if a seedling has some elongated growth.

The advantage of T5 is that they are very well suited for vertical growing when you have shelves. Or that they are cheaper to buy initially. Or that they produce some more heat which might be desired in an otherwise unheated room. LEDs will not be worth the money if you use the light for 12 hours a day in February to April for 2 to 3 years. If you are going to spend more on electricity, for example because you know that the coming 10 years you will use it from December until April, and run it 16 hours a day, then the cost of the light is going to be smaller than the cost of the electricity. And then LEDs become cheaper.

Also, the diversity of products among LED grow lights now is pretty high. The traditional light bulbs that can compete with LED grow lights are 1000 watt HID (HPS/MH) lamps. Few people would want to run 1000 watts worth of lighting indoors. Of course the other alternative are actual fluorescent like T5.
Of course T5 and T8 are size formats, so you can also buy LED loaded tubes now.

There is no reason to buy 'LEDs of dubious performance'. There are tons of Youtube channels that test LED panels of major manufacturers using high end light intensity meters that specifically measure the intensity of light that plants would use for photosynthesis (as opposed to either photon or energy flux or apparent brightness).
While there are tons of dubious LEDs available on sites like Amazon or your local Home Depot or Walmart, it is not so easy to buy a independently reviewed T5 fluorescent bulb, because people don't really bother. Also, LEDs seem to be a fundamentally more reliable technology. One issue would be thought that individual diodes on a LED panel may break. So over the years (or decades?), you will slowly lose more and more of them. But for a fluorescent, one day it will just stop working and you know you need to replace it.

I can give recommendations if you specify how large your area will be and how long you plan to grow them indoors.

Thank you! That’s a lot to think over Recommendations would be most welcome, too. I am looking at a light 4’ x about 11”, with 4 bulbs (fluorescent). This is just about exactly what I’ll require for seedlings. Oh, and they will be in a western slightly by south window. It hangs from the ceiling (much cheaper than comparable with table). The brand is Durolux, and also looking at Vivosun, on Amazon as it happens lol. As far as, dubiousness haha, leds of these brands seem to be straight white full spectrum bulbs. Perhaps give me alternatives for led and fluorescent? It would be much appreciated

 

[penumbra]

This one by far.
The others are not even worth the money or effort because they have zero white LEDS.

Full Spectrum (100 red and 50 blue bulbs) is NOT full spectrum, at all.

One can debate about how warm or cold the white LEDs should be. And about how many red LEDs to add.
Usually, what is best is a mix of cool and warm white LEDS mixed in with some reds.
But there is some debate to be made that you want the spectrum to be higher on blue light at some point in the growth cycle, because this will produce really compact plants and shorten internodes by a lot. Which can have several advantages, both bonsai and non-bonsai related.
But initially, I would say it is pretty good if a seedling has some elongated growth.

The advantage of T5 is that they are very well suited for vertical growing when you have shelves. Or that they are cheaper to buy initially. Or that they produce some more heat which might be desired in an otherwise unheated room. LEDs will not be worth the money if you use the light for 12 hours a day in February to April for 2 to 3 years. If you are going to spend more on electricity, for example because you know that the coming 10 years you will use it from December until April, and run it 16 hours a day, then the cost of the light is going to be smaller than the cost of the electricity. And then LEDs become cheaper.

Also, the diversity of products among LED grow lights now is pretty high. The traditional light bulbs that can compete with LED grow lights are 1000 watt HID (HPS/MH) lamps. Few people would want to run 1000 watts worth of lighting indoors. Of course the other alternative are actual fluorescent like T5.
Of course T5 and T8 are size formats, so you can also buy LED loaded tubes now.

There is no reason to buy 'LEDs of dubious performance'. There are tons of Youtube channels that test LED panels of major manufacturers using high end light intensity meters that specifically measure the intensity of light that plants would use for photosynthesis (as opposed to either photon or energy flux or apparent brightness).
While there are tons of dubious LEDs available on sites like Amazon or your local Home Depot or Walmart, it is not so easy to buy a independently reviewed T5 fluorescent bulb, because people don't really bother. Also, LEDs seem to be a fundamentally more reliable technology. One issue would be thought that individual diodes on a LED panel may break. So over the years (or decades?), you will slowly lose more and more of them. But for a fluorescent, one day it will just stop working and you know you need to replace it.

I can give recommendations if you specify how large your area will be and how long you plan to grow them indoors.

This is the long version and is much appreciated by those who need to know. I just didn't have the energy to get into it so thoroughly. Very well reasoned.

Okay, this is good to know. The led sellers do claim that Kelvin range in their white bulbs. What is the advantage of fluorescent over led? I don’t doubt it, just curious as to why. Is there a brand you would recommend? Thanks

I use mostly LED for general plant growing and maintenance inside but prefer T5 for cuttings and seedlings. It is mostly a personal thing based upon my own observations. Mileage may vary.

Thank you! That’s a lot to think over Recommendations would be most welcome, too. I am looking at a light 4’ x about 11”, with 4 bulbs (fluorescent). This is just about exactly what I’ll require for seedlings. Oh, and they will be in a western slightly by south window. It hangs from the ceiling (much cheaper than comparable with table). The brand is Durolux, and also looking at Vivosun, on Amazon as it happens lol. As far as, dubiousness haha, leds of these brands seem to be straight white full spectrum bulbs. Perhaps give me alternatives for led and fluorescent? It would be much appreciated

I like the 4 bulb units but also use 2 bulb units depending upon the space. Don't buy cheap units, they will not last. Both Durolux and Vivasun are good units. I have used both but most of mine are Durolux, for no particular reason. I replace my bulbs annually. Some people do more and some less. Again, it is a preference based upon personal observation.
The very best to you and your seedlings.

 

[Nybonsai12]

I’ve started trees from seed in the middle of winter for years with T5 6500k fluorescents. cheap, effective and they don’t get hot. black pines, tridents, j. Maples, cork oaks, zelkova have all done fine starting under this setup.

 

[Glaucus]

Thank you! That’s a lot to think over Recommendations would be most welcome, too. I am looking at a light 4’ x about 11”, with 4 bulbs (fluorescent). This is just about exactly what I’ll require for seedlings. Oh, and they will be in a western slightly by south window. It hangs from the ceiling (much cheaper than comparable with table). The brand is Durolux, and also looking at Vivosun, on Amazon as it happens lol. As far as, dubiousness haha, leds of these brands seem to be straight white full spectrum bulbs. Perhaps give me alternatives for led and fluorescent? It would be much appreciated

4’ x about 11”? So 122 cm by 28 cm? So it is an elongated area? Most lights are good for a square or near square area.

Many of the LED grow lights provide enough light to grow cannabis plants. And those require a lot of light.
So a quantum board-style LED panel of 100 watt would be:
Senelux SE-1000
Mars Hydro TS1000

These or similar boards are good to buy if you want to buy a LED grow light. They are good spectrum, high efficiency, value for money. But they are big enough to grow 1 cannabis plant to maturity. That is the lower range in terms of light output. LED panels with less light than that are very rare, because there is basically no point in putting them on the market. And these products are also not elongated 122 x 28 cm.

So if your goal is to germinate seeds, are already near a window, and you plan to sow not to next month, and your plan is to move them outdoors in spring, you do not need a 100 watt high efficiency quantum board LED.
You can basically rely on your window for the first weeks, then put near them any type of (white) light and use that light for a few weeks.
Then move them outdoors.

Basically, get a 20 to 50 watt T5 that is in the 3000K to 7000K range.

 

[penumbra]

4’ x about 11”? So 122 cm by 28 cm? So it is an elongated area? Most lights are good for a square or near square area.

This is one of the reasons people use T5 lights, though you can find LED shop lights that have a decent spectrum for about $30 each or less.

 

[Glaucus]

Any white LED in the 3000 to 700K range will have a good spectrum. The point is, no one is going to put a high efficiency good quality LED panel on the market that can illuminate 1/4rd a cannabis plant. The reason these products as so good is because of indoor cannabis growing. Not because people want to germinate their tomato seeds or chili 2 to 3 months early indoors, using a grow light.

For that reason, buying a <80 watt LED light grow growing plants is a bit of a crap shoot. But if you are in that range, you likely don't care about efficiency/electricity costs.