Day 21: First topping. Happy to removed the light-stressed part of the plant from the equation if only for cosmetic reasons. I waited for 5 nodes before the topping. Day 22: Godammit, the light failed again. Turned it off and waited for it to cool down. Turned it back on and it worked. Lost 1 hour of light. Day 23: Because of previous light stress and canopy temperature, I felt that 35cm is a good distance for the light. Day 25: First LST on the new growth tips. Started the mainline. Day 26: Again the light is failing to come on. I rewired once again, cursing my very existence, and it worked again. Again lost an hour of light in the morning. Continued refining the LST, and seeing how far I can push it. Noticed a slight tear at the base of one of the mains. Since the plant energy is coming from below and there is no noticeable affect on growth I'm going to ignore it. Checked the roots - look healthy. Though the new growth tips are not completely symmetrical, those leaves look good enough to eat. Trimmed the excess fan leaves. Topped up with a small amount of nutrients. Day 27: light didn't come on again. I rewired again, but this time it was stone cold refusing to do anything. Again I cursed my existence and all of life. Returned to grow store, turns out bulb was defective after all. Again lost 4 hours of light. But at least now I know the problem is solved. Rene at the grow store is a champ though, very helpful guy. The new bulb is noticeably brighter also. Maybe this was affecting growth? Also once this issue was fixed, I noticed some small amount of nutrient burn on the leaves tips. Rebalanced nutrients. Was 1.9 mS/m lowered to 1.65 mS/m, then to 1.48 mS/m. Must be more careful in future when upping the dosage but the water conductivity is now less than before (1.55 mS/m) so this should be ok. Also lowered pH of water slightly since it was 6.0. It's currently showing 5.2 but experience has taught me that this measurement will comfortably go back up to 5.7. water pH is seemingly constantly rising as the plant grows, and adjusting pH is really more art than science. (Edit: It was 5.7 the next morning, so ya ... )