Frigaultanswered grow question 4 years ago Ts2000 around 30-36 in fir seedling. You ket it grow into it. Or liwer slighly if the olant strecth. The older the pkant gets the mor light it can handle. 24-18 in vedge. Around fkowering yiu startbaroun 18. Work to about 12 and last few week you back the light to aroun 18. but you look for sign ogbstress. Every strain is difrent some can handle more the others.. so adjust accordingly