Just a quick one, I'm looking into buying a grow tent with a 400w hps and a 5inch exhaust fan (I'll also have a fan on the inside of the tent for air circulation and to strengthen the stems) Would it be safe to leave it unattended for 2/3/4 days at a time? Cheers
If you have your environment dialed in and lights on timers, yes it is ok to leave your plants as long as needed until they need water. It's easier when the plants are older because by that time you'll have a good sense of how often things need to be tended to. In general though, I try not to leave my plants longer than a weekend without somebody (wife, very trusted friend) checking in, even if it's just to make sure the light hasn't fallen on the plants, no electrical hazards, etc.
I have to check mine more frequently towards the end of flower because in have to dump the humidifier every night. I am going to put it on a shelf up high so I can use the gravity drain on the bottom. Then will only have to check every 3-4 days. There's too many variables that could go wrong to let it go longer then that, light out, timer out, branch fell over from weight.......