I dim mine for sprouts... Full on for flower. If your lights are capable of par values over 1000 and you run out of grow room height, I suppose a little dimming may be in order to not over light them. They can only use so much light. Increase it, and it will demand more nutes. Problem, usually they can only uptake so much,32 days. Buds are coming along nicely. I have read a ton on these pages. Yet i don't see a lot of you guys mentioning dimming your LED lights. Us there an opportune time to dim them?