1/13/14

E-mail - Comparing HPS and LED

I just read your article on LED vs. HID. My question is side by side how much is the yield affected comparatively? When grown using 300w led vs 400 w hid in flower stage
Sent from my iPhone

Hello,
  I have not done a "side by side" experiment, but I do agree with my article comparing HPS and LED, that LED's are comparable to HID's, even in flowering.  I have used a 400 HPS and a 300 W LED in the same grow area at different times with the same plant type.  They were comparatively equal.  The plants were different, (same strain so genetics were the same)  The plants under the HPS were bigger, with longer node length which was due to both the increase in yellow, and the fact heat was a problem, the temps were in the 90's when the light was on.  Under the LED, the plants were more compact due to more blue light and also that with the LED, the grow area never got above 85F.

The plants were bigger under the HPS, but I'd say that when it was time to harvest there was not much difference between the two.  If you are using a 600 w or 1000 w you might want to use two LED's to get the same area coverage.  The LED's are more focused so when you get into the larger sizes of HPS with their reflectors, they can cover larger areas.
Good Growing,
Dr. E.R. Myers