what type of nutes are you useing? specific npk? any suppliments or hormones?
keep the temp at 78F for the whole growth cycle. that is the optimal tem for cannabis plants. helps them grow, absorb and process co2 and nutes, and prevents evaporation from the leaves. sharp changes in temp will stress and shock marijuana plants. try to monato and maintainr the temp and never let in change too drasticly.