SHOULD I HAVE THE UVB ON ALL THE TIME? August 21, 2019 20:07 Updated UVB has proven to be very effective in the last 2-3 weeks of flowering. Related articles DO OTHER GROW LIGHTS HAVE UVB? HOW DOES UVB HELP PLANT GROWTH? HOW DO SOLARSYSTEM LIGHTS COMPARE TO OTHER LED GROW LIGHTS ON THE MARKET? DO I NEED TO COOL CALIFORNIA LIGHTWORKS LIGHTS WITH A FAN OR AIR CONDITIONING? I'VE HEARD THAT LEDs ARE GREAT FOR THE VEGETATIVE PHASE BUT CAN I ACTUALLY FLOWER WITH LEDS?