I had this issue in my first grow. This is kinda contrary to everything all these way more exp growers are saying, so I'm not saying this is the problem, this is just something that happened to me. My leaves started drooping and I began trying to figure out why. What my problem ended up being was that I was watering on a 4 day schedule. At day 3 I'd lift the pot and it would be light, so next morning I'd water. What I didn't take into account was the plant was getting bigger and drinking more. The next time I went in there and lifted them around 36 hours after the last watering and they were already light. I needed to water the next morning. After that I just started lifting my plants everyday. It stayed on every 2 days until I changed the light cycle, then it went back down to needing it every 3. I was really hesitant to write this bc I think everyone is prob right on with their assessments. It was all just pretty similar to my situation so I shared. Good luck with it. I want to run Solfire so bad.