Experiment: Red Light vs Blue Light -How Spectrums Affect Plant Growth- LED vs CFL

Blue light vs Red light. Which is better for vegetative growth??? Instinctively, the answer might seem obvious: Blue light is for vege! That basic mantra has been …


  1. I think that this experiment was very eye opening. However, I think that the experiment was not fully valid. This experiment could be repeated with the same procedures, however you should have used cuttings from the same plant for this to be “unbiased.” Otherwise, I still believe that the experiment was helpful and I will refer to this video in the future nonetheless.

  2. Hi, can i ask you one thing? <( ^ – ^ )>
    Can you put same kind lettuce under same red led light with same distance/water etc for 2 weeks, and then change the red led with same blue led for one week, and then change the blue led with same red-blue led for one week. In theory, it could be the best grown lettuce! :3

    Stage 1) Under the red led light, lettuce leafs will grow as max as possible for 2 weeks.
    Stage 2) Under the blue led light, lettuce leafs would grow towards the led so leafs will be taller for one week.
    Stage 3) Under the red-blue led light, lettuce leafs will be thicker and crispier! for a week

    I think this can beat the growth of the lettuce under the white led for 4 weeks :d

  3. Thank you for this video. Great analysis. I have 2 citrus plants/tree (Kaffir Lime and Orange) and Jasmine Sambac plant that I bring into the house every year to keep them alive from the cold in the Northern Virginia. Every year, I barely kept them alive with the regular LED light bulb as the leafs kept falling off from these plants. What type of bulb would you recommend to use to keep them alive over the winter and from keeping the leaves on these plants? Thank you.

  4. Great experiment ! I remember researching what the Japanese came up with from their studies years ago…..very similar. From my own, i found adding cold white LED's,(15000k) to the red and blue took care of the minor color needs of the plant….in effect, rounded out the plants diet. Thank for posting a great video !

  5. What variety of lettuce is that? Nvm, but dont you think using different varieties might be bad for an experiment like this where you only do one trial per light.

  6. Great video, very educational. I have a full spectrum led grow light that has mostly red leds. I've been looking online for one that has more blue than red. I'm new to growing but a friend gave me some Carolina reaper pepper seeds and I'm trying my hand at it. I don't have hydroponics, just soil and fertilizer. Is there a certain full spectrum led light that is dominantly blue over red? I'm looking for only 50-100 watts. I also have a 65 watt, 5000k, 4300 lumens large spiral cfl.

  7. Dear AlboPepper – Drought Proof Urban Gardening

    I would like to grow garlic in aeroponics System. Can you help me, what kind of (color) led lights do I need? White and red&blue or only white or other?

    Thank you for your answer in advance


  8. I came across this looking for info on red vs blue light for my planted community freshwater fish tank. Fantastic information! Thanks for sharing all your hard work with us nerds;)! Great job! Love it!!

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