@popcornsutton, with this light it comes with 2 of them things, god knows what they are call lol but I think one is at around %75 and the other one is at like 50%, I don't have them on the same level because the light is already spread all around the tent so I thought it be better and plus it's not to intense on the plants but yeah between 50% and 80% I think is best at this moment in time till later down the line when I up it between 70 and 100%. Most times I just play around with it to get it to my liking