I am new to the group and happy i found this site. I am new to LED growing and have found there is so much bad information on the internet. I am using 6 SF220's in my grow room. Trying to find good information on proper distance for my lights has been tough. After trial and error what i found was during veg 24" provided good stretch and node spacing. I did some at 12" and found the plant height to slow but become bushy. Not a bad thing i suppose if space is limited. Distance during flower was 18". So far good results. But the whole "closer is better argument" had me chasing my tail until I figured it out.