Fred, That's a topic that can be as complex as you want to make it (there's a lot of research, but also a lot of folklore, out there), and you can spend a lot of money on fixtures, but my opinion is that if you don't care about tweaking every little thing to the utmost, then you can simplify it down a lot and for a lot less money. I've grown and do grow under both artificial light and in a greenhouse, and replaced my last fluorescent fixture with an LED several years ago. Mostly carnivorous plants, orchids, and aroids, but there are some bulbs and other geophytes in there too. If you want to go into the science and get recommendations for some reasonably priced full-spectrum fixtures designed for plants, I suggest looking at the articles and blog entries from Kelly McCracken of High Desert Orchids: https://highdesertorchids.com/blogs/… I used to do a talk on this topic for orchid people, now I just point them to Kelly's stuff. She does a great job, covering aspects most people don't. Some are technical, but she's also good at presenting those in a clear way that doesn't require a technical background to understand. For myself, I just buy cheap, linkable, 4-foot LED shop lights at Sam's Club for about $30, 5000 K color temp. Not perfect, and the serious light people will sneer at me, but they're cheap and convenient, and plants are amazingly good at capturing photons, even in the green spectrum where we tend to think they're inefficient. The only problem I had when I went from fluorescent to LED was I had to raise the lights several inches and/or reduce the time on a little. The LEDs were, from the plant's perspective, more intense. (Remember that lumens is a unit designed for how human eyes see light and doesn't reflect - no pun intended - how plants use light, and that light emitted from LEDs is probably in a different pattern than that from your fluorescents.) In some cases I have one LED shop light, with a reflector along the back, where I had previously had two fluorescent fixtures. And finally, I would definitely and absolutely avoid the "purple" LED fixtures - those that are a mix of red and blue LEDs. Steve On 1/10/2023 12:27 PM, Fred Biasella via pbs wrote: > Hello Folks, > > I'm sure there was a discussion about changing fluorescent lights over to LED lights a while back but I don't exactly remember (CRS ya know?). I was just online looking for replacements and got all twisted up with the spectrum, kelvins and intensity. Which spectrum do you all use so the plants grown indoors get the proper light spectrum/exposure and not cook them? I'm very fortunate in that my plants are growing in my closed in, heated, southern exposed porch but I think they would grow better with different lights. Any Help would be greatly appreciated :) > > Thanks, > Fred > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > http://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > PBS Forum https://… _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> PBS Forum https://…