Grand Daddy Purple

4/1 AM (Day 26) - Topped at the 6th node for two of the three GDP's. Not touching CD#4 yet since it is still on the small side and I want to give it the best fighting chance to grow out. I'll give her a few more days to put on leaves and see how things go. Overall, three of the four total plants I started with seem to be adjusting just fine to the increased PPFD (hovering around ~550), and a slight increase in average temperature (now hovering around 77F). Height has increased significantly, now ranging between 8-9" (all GDP are at 9"). Unfortunately, the one plant that previously showed some mottling in the leaves seems to be in decline. At least one set of leaves is heavily mottled with brown spots. The reading I've done suggests either a pH imbalance, or problems with the root system. Growth is definitely stunted. I've considered abandoning the one so I can focus on the three that seem to be unaffected, but it's still alive so I'm giving it some time to see if things straighten out on their own. New growth does not exhibit the symptoms. I'll post additional photos either later today or tomorrow, depending on the weather. Getting good photos under HPS is a challenge. I'll power it down to get a full capture. Given this is my first attempt, I'm not afraid to show both successes and failures. All four have received the same treatment, and been in the same environment the whole time. It remains a bit of a mystery why one specific plant seems to be perpetually unhappy. I have not over watered. If anything, I've tended to let things dry out considerably between watering. For example, today is day 3 since the last water-- and the healthy plants seem perfectly fine with that. My pH meter has been calibrated twice out of an overabundance of caution, so I don't think that's the issue. Also, I have not been adding nutrients except for a little CalMag and a very small amount of unsulfured blackstrap molasses. 4/1 PM (Day 26) - Added additional photo with lights out, which includes the GDP with the problem shown in the pics. Close-up available for any who may have suggestions, other than leave it alone and continue with nothing more than pH adjusted water.