@Mr_weed_pt, 81 to 68 at night is pretty big temp fluctuations. Early flower and veg anything over 10-degree change will signal the plants to stretch. Try to keep the change in temp between lights on and off under 9 degrees until your plants stop growing vertically. Then you can allow larger changes in temperature and it will instead signal the plant to cake up and bud up more. This will help you control your growth a lot. Keep up the good work man