Hi, I don't think your problem lies in the humidity but rather in the wrong pH value. If the information in your diary is correct, a pH value of 8.02 is way too high, and the plant won't absorb the nutrients you're giving it (nutrient lockout). Adjust this when watering; it should be between 5.8 and 6 for small and young plants, and then you can go up to 6.5 during the flowering phase. Give that a try. If she improves, give her some nutrients, and don't forget, if you're using LED lights, you also need CalMag.