No chlorine, only rain water here.... I think it is a minor problem, just the very small end of the tip and it doesn't spread or get worse.
I have started transitioning my way into flowering, swapping 6500k bulbs for 2650k, one at a time. I will be decreasing the lenrth of lighting as well over the coming weeks. I can hardly weight. My main big plant is My one main big plant is about 9" tall and about 10" wide. Its the picture of health except for the minor brown tips problem. It will be 3 weeks old Monday. My one week old seedlings got repotted tonight due to them being stretchy. I reduced their numbers to 3. They have their own light now so they should be quite happy.