anyoneder

@LuckyLuke, Ohh right. also i forgot that you have one plant that is not an auto right? So that one might grow quite a lot more if you stay on 18-6. While the 3 autos will probably not get tooo much bigger but will be finished faster and then you might re-pot your white widow in a bigger pot so that this one can possibly grow so big that it fills the whole tent. Maybe that way you can make up for some of the "lost" yield due to inexperience. 💪 (The pot sizes you use is fine for having 4 plants in a space like that but will probably be to little for one plant for the whole space.)

Also you are not in veg any longer.... (That might also be a reason why the look underfed. Flower takes more nutrients.)

@LuckyLuke, Okay cool. Since you can't quite know how they will react just check every ~2 hours if you can. The signs that they get to hot are widely discussed on youtube. I had my light too low once and immediately saw it by having the highest leaves developing brown dried out leaf tips, so watch out for that. (Of course if one where to overfeed nutrients that would also lead to brown leaf tips.) 33°C is really quite hot. Where is that measured? Whats your room temperature? (Not grow-box temp.) Maybe if you had like 26°C of room temperature you could bring in colder air at the bottom and exhaust the hot air of your grow light from the top. As heat always moves upwards that might help keep your roots cool. (They are the most vulnerable to heat stress. Your leaf tips can transpire water if they need to and cool themselves down but if your root's get to hot they can't function properly and then the whole transpiring collapses and your plant just dries up.)

Hey, just wanted to give you a view tips to try out: - It looks to me like your light is way to high for your plants. They look like they really try to stretch towards the light. This plant is supposed to only grow to 80-90 cm outside however yours are already that tall yet not very bushy. - You might want to read up on how high your particular grow light should hang above the highest point of your plants i would guess round about 40 cm maybe 50 but you post that it is 85 cm up. Light intensity reduces quadratic meaning that you might only have a 1/3-1/4 th of the strength of light that you where going for. (Hold the underside of your arm round about where the top of your plant would be an check if you can leave it there without feeling any real "warmth". Your arm should stay fairly cool but you might feel a little of the infrared spectrum as light "heat".) - Also your plants grow with different speeds. So to counter that you might want to raise the taller plants closer to the light so that the lower ones are still trying to stretch towards the light more but the taller ones are getting enough light to start growing bushier and less much hight-wise. (Of course they also will still grow height wise but not as much.) - If you absolutely have to have the light that high then maybe switch to a longer light cycle. (One can roughly say that plants average the amount of total light they receive per day. Meaning that if you have like 20% to few watts of light for your grow you can make up for that by having the lights on for 20% longer. (This though gets problematic in flowering and with non-autoflowerings as they need the 12-12 cycle.)) I'm not a pro but those are my 2 cents of what i have learned so far.