This just happened. About the same day i moved it from a greenhouse to this growbox. My guess is that is burnt. Because after the first 18hrs of having it under 2 cfl bulbs (totaling at 136W (soft white 2600K). It grew 3 inches and was way too close to the bulbs for a few hrs. But since then I switched to flowering(12/12) and keep bulbs 4in away from the plant. Hope this is nothing serious
Nothing serious. My plants do it from time to time. Your heat might be a little high and that could cause it.
Plant stems often take on a purple hue when they are stressed. Its normal and will usually go away in a couple weeks.
Purple stems are pretty normal. If your plant was being burned, it's more likely the leaves would show it than the stem. Stems can turn purple because of cold temperature, certain deficiencies, or sometimes stress causes it. Then there's the fact that some strains will just grow with purple stems because that's just what they do.