Hey guys,
I realize par is a better measurement than lux for plants, but a lot of us probably still have lux meters lying around, not to mention that lux meters are nice and cheap…
Lux should still give an idea of how even the lighting is etc.
Anyways, I’m wondering if any of you cob users users measure lux at canopy?
I have a plant that cannot seem to go above 15k lux without yellowing of the upper leaves.
Anyone have any lux data that they could share with us from successful grows with cobs?
People get hung up on PAR, but honestly a hobbyist usually doesn’t need more than a basic lux meter. Sure it’s nice to measure PAR, but save yourself $250+ and use lux instead. It will pretty accurate as a relative measurement as long as you compare between LEDs of the same color temperature.
That being said, 15k seems unusually low for any kind of light. Are you sure that you are measuring directly underneath the COB, and not off to the side? ~45-50k is generally a good lux number for flowering. 15k is more like what I’d use very early… like 2-3 weeks after germination.
Hey man, thanks for the reply!
I measure basically right over the top of the center cola. I measure same place each time for consistency.
She is an autoflower so I run my lights 24/7 even during flower. Since she is getting 12 more hours of light than a photo would in flower, I’d expect the number to be lower but not 15k…
I actually gave her her first night period of 4 hours last night to see if she just needs some rest. I’m going to keep her on 20 on, 4 off schedule and see how she does.
I agree Lux is an ok measure for light intensity, even for leds. It’s not perfect but it helps ballpark.
Thanks again!
One thing about COBs is they can be very intense right underneath the center, and disperse very quickly on the edges. You might want to see if any other parts of the plant are receiving more intense light.
Also – I’m not really familiar with autoflowers as much. Maybe that has some differences with light intensity when you’re going 24h.