Droopy leafs again

heat mat may not be best idea for a mature plant. if floor is cold something it can sit on can help. you might be warming substrate much more than the air. warmer temps = less oxygen for roots. substrate can be colder than the recommended air temps. warm the air, not the substrate. 22c isn't so bad. it's probably warmer directly under lights, too. all sorts of different reasons can cause droopy leaves. after looking at diary i have some other ideas... You've got 200w in 4 sq ft of space running 20 hours per day. You wouldn't need 50w per sq ft on a 12 hours per day schedule. efficacy of that light would matter here. 2,3 umol/j efficacy looks accurate. you are giving 1200+ PPFD over 20 hours is over 86 DLI. you are giving way too much light even for a co2 rich envionment. give less light. reference a DLI table. i have you your ppfd for 4 sq ft with that llight. you may need to dim it a bit. you'd only need 9 hours of light to max out for ambient co2. Or, increase distance from canopy. 24 inches is already 'dimming' it a bit as far as max intensity in any 1 spot. the 1200 plus PPFD mentioned would probably be 18 inches or so relative to area of coverage. just an educated guess. that light looks like it has well-distributed diodes.