I’ve had my SF4000 set at 30â€@60% for the past 2 months. I saw all the YouTube reviews about how bright these lights are, and how much higher they need to be, so I followed a bunch of suggestion in the comments.
A couple weeks ago I read the GWE Lux meter article and was going to buy the model the site showed but saw Dr. Meter’s new one for LED and bought it, the LX1332B. After doing some tests at canopy level I raised the light to just under my eye level when standing, I’m 6’1â€. I got 250 x100 (25,000) at the top of the canopy with the light turned to 80% and my tent really lit up. My plants are seeming to like it so far.
I’m going to take it up higher and try to maintain the 250 reading by turning up the dimmer even further. There just isn’t enough about this light to get confirmation on hanging height and at what dim level.