I prefer to build my own grow lights since I can have full control over the output. The parts will be arriving late unfortunately, and the suspicious $5 50W (30W as measured) grow light (that I ordered out of curiosity) arrived first. The seeds I've planted have sprouted exactly when the DIY grow light parts would've arrived.

The cheap grow light flickers at what seems to be 120Hz. Is there any info on what effects this has on plant growth?

The closest I could find is this study: Effect of Flashing Light on Plant Growth Rate. They flash it on the order of 5 seconds though, and not 60Hz/120Hz.

  • I doubt your plants will notice such a high frequency. The phosphors in the LED's likely don't even have time to get down to zero emission. Thar said, when the rest of your lamps come, they'll probably be out of phase with your current lamps. BTW, plants do notice short flashes of light at night through a P450 like mechanism. Feb 28, 2021 at 19:18
  • @WayfaringStranger It indeed doesn't notice at all. I've managed to get access to the research paper I linked and it basically has no effect it seems, if my interpretation of their chart is correct.
    – Aloha
    Mar 6, 2021 at 7:27

1 Answer 1


It has no effect as far as I can research. As @WayfaringStranger has also pointed out, the phosphors also presumably don't have time to get to zero emissions in that short of a time period.

This chart on the research paper I linked has a time versus weight gain chart (no permission acquired): enter image description here


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