Here are some updates since using the 300w (7172 lumens) LED that Nullzero recommended. You can see the etiolation without the light and the drastic change when the LED was introduced. I know I should get rid of the etiolated growth but I decided to let it go for now. After adding the LED, the four cuttings each have a new shoot that appears to be growing really nicely. The only one not growing is the one in the picture that looks like its been cut. It came this way from Home Depot when I picked it up i Miami. Not sure what I need to do to get this one to produce a shoot.
I didn't buy a grow tent yet but bought about 10 Mylar survival blankets and put one on the wall. It appears to be growing very well without completing enclosing the plant but I'm guessing it will grow faster if it were enclosed. I'm letting the LED run from about 7am-1am each day.
I also have two CFLs shining on the shoots. One is 6500k (1600 lumens) daylight @ 100w. The second is 2700k (2300 lumens) @ 150w. I'm not sure which is most beneficial for the plant. I notice 2700k CFLs are used often with the idea that brightness is more useful that a daylight. Any thoughts?
Thanks for everyone's comments!
Hey, really cool setup. Looks like you're getting nice growth! Couple of thoughts:
-More light the better. The red spectrum (2700k) is more for bloom while blue or daylight for growth. When using LEDs, it doesn't quite work out that way, though the "purple" look is made up of both red and blue. When Null and I were talking LEDs before, that was specifically regarding red LEDs in a certain spectrum to force the plant to flower. It seems 660nm (roughly 2700k) is the key, but that's re: outdoor flowering.
-Have you seen Coplantnut's setup? I think he works at or owns Black Dog LED in Colorado. They make really high end LED grow lights with 1000s of watts. His indoor setup is amazing. That said, he mentioned he's never been able to get dragon fruit to flower indoors. It's possible they need that much light. Or he's not giving the plant enough light hours or something. Or I could be remembering everything wrong.
-Also, dragon fruit is a photo-period sensitive plant, it needs a lot of sun hours to know it's time to flower. Mine only just started blooming. I tried to force it with 300w equiv CFL at 2700k and bloom fertilizer. Of course, we're now into the period where it flowers anyway, so I'm not sure if the light and ferts are doing anything.
-Are you planning on wheeling it outside in the summer? That may work for blooming. Also, remember, the thing gets crazy huge. Just one stalk will take over your entire room there. I only have 2 stalks coming out of a 15 gal pot and the top easily takes over a 6ft x 6ft area.
-Also, you can probably leave your LED lights on 23 hours a day. Indoor growers often really push the light hours to just bake the plant as much as possible. Maybe even 24 hours. I'd do some research into indoor cactus propagation to see if anyone has tried it. 300w of LED is a lot of light, but it's still nothing compared to tropical sun, which is roughly the equivalent to a 100,000 lumen grow light. Your LED is probably closer to 20k lumens because of the way it focuses on just red and blue wavelengths.
-Heat. They love heat. Mine grow like crazy the hotter it gets. I'd say close up that little grow room you have started and let the heat build up. Or put a heater next to it. Hot and dry, 100 degrees is their happy place.
-Keep going! You may end up being the first person to successfully get dragon fruit to fruit indoors.