thats around 11 inches from your canopy. Mine are currently at 11 inches from the canopy and my intensity is 100%.
Ideally i would prefer 15 inches from the tops, but they seems to be handling 11 inches at max intensity. I typically don't push it that hard but my height is maxed out and i turned it to 100% just because i like to experiment and since i have no one to answer to but myself, and weed is worthless where i live now, i don't care if i fuck them up a bit in the name of science!
P.S. I make edibles. I put 2 oz. of bud into the magic butter maker and about 1 lb. of butter and make gummies and fat bombs with coconut oil. I just finished flushing my plants and i decided to celebrate with a 400mg edible! These fuckers have caused me to green out once, and come very close another time. I took one yesterday and i slept 17 hours! haha (i'm off work till christmas)