Mistakes I made

[micmac]

micmac u need to settle down man, a 600w HPS in winter will still put off heat enough to warm a 1.2m tent you will only need the heater on a timer once your light turns off just to maintain temperature

 

do not run your light without the fan working otherwise you could be putting on display the biggest bon fire in your neighbour hood when your house burns down

 

you can run your exhaust fan on a thermostat there are combined thermostats for heating and cooling in one unit this would be the choice because your running a 600w light which puts off plenty of warmth the other option is to use a fan speed controller but it will require u to keep checking on temps untill its dialed in

 

your leaf curling is you are running your light too close to the plant and u don't have the medium sufficiently moist enough for the plant as u mentioned u let it dry out

 

once u have the above corrected if your humidity is still low under 50% you will need a humidifier to raise the humidity to around 65-70% seeing as your in veg

 

you also have another problem the plant looks pale u may have a deficiency

why does the humidity go down so much as already have humidifier ok I turn the fan back on do you think it might be wind burn I put a smaller fan over the humidifier to blow across top of plants

[micmac]

why does the humidity go down so much as already have humidifier ok I turn the fan back on do you think it might be wind burn I put a smaller fan over the humidifier to blow across top of plants

i put on outside a week ago new growth is good maybe the light was to close not sure I can rely on weather station reads different even when the sensors are in same spot