First time poster and obviously noob at this. Been reading this forum and researching for almost 2 months now. The following is some info to help you diagnose my problem. My grow cab is roughly 2ft deep, 3ft wide, 4 ft high. Inside is lined with reflective mylar, 4 cfl's from a bathroom fixture, 1 120 mm fan venting out, with another small 6" fan inside blowing air up. Plant went from soaking in a shot glass, straight into FF Ocean soil in a 3 gal pot. Been watering it everytime the soil feels "dry" about 2 inches down(using distilled water). My problem is the last week has seen the exterior edges of the leaves turn yellow. Some of the smaller leaves are canoeing downwards and the tips are turning brown. The plant seems healthy, and the leaves didn't feel super dry or anything. I currently haven't used any nutes, and am wondering if this is a watering problem? heat problem? humidity problem? Sorry about no pictures, I may put some up later. Not too much I can do about the heat because I plan on leaving it in the garage until completion. Thanks in advance.