How should I adjust my HLG 550’s and at what height above canopy.
Not really a certain height but more so a certain DLI or umols is what your going for. Heres a screenshot I took a while back as I had the same questions as you before. Check your umols with a lux meter, photone app, or even use your phone if its an android and type in (star, pound,0, star, pound) and go to sensor. In the sensor setting you should see lux somewhere and to back out completely just spam the back or home button