I am running CO2 and I run the plants as close as 8” with Fluence and about 18” with Gavita
To be honest I have an Apogee light meter and I never use it. Once you start getting in tune with the plant you get an idea of what they can and cannot handle. You will hear people say oh I start counting flower days once I see the little cotton balls on the top. About day 11 to 13. This is due to lighting. The breeder information is more than likely tied to 1000 watt double ended HPS.
Last night I had to start tuning down the watts on some plants growing under Gavitas. Day 39. If I run them at 100 percent every plant I have ever done it to Foxtails like no tomorrow.
CO2 helps but I have had the same numbers without CO2. It’s been a while but I might have ran those a little longer.
It seems insane to me that the top light manufacturers are never really mentioned.
The comments above are a big part of why I detested these threads. There is usually 3 to 4 of them a week and people with one or two grows with XYZ light are always quick to jump on about that XYZ light.