DIY Growbox Indoor Durban Poison

Week 6. I was on holiday for 5 days. I set up a slow watering system and the timer in my absence. I didn't put the fan as it will move the smell with the inside air with no intake from outside ambient air. No carbonated water either. Back home and I can see that everything worked out almost perfectly I shouldn't have set up a slow watering system I should have make it stronger. The humidity and the temperature dropped. I think I will start reduce the light schedule to 12-12 because the space between the light and the leaves is reduced to 28cm now I'm expecting 6 weeks of flowering and I don't to chance having under 20cm space in between. Some leaves are yellowish and some are dead in the lower part of the tree I think it's because the light not getting all the way there?? 🤔😕. Might need some trimming? Or else? The clone died R.I.P, there was moisture on the main part I'd assume it's a lack of air and an excess of humidity. Still wondering if I will give it another try... we'll see!