red or purplish streaks in the stems, are usually caused by too high a temperature differential, between night and day cycles, and harmless ... it can also be caused by a phosphorous deficiency, not quite so harmless ... be aware, when using reverse-osmosis water, the minerals (calcium, phosphorous, magnesium, iron, potassium, etc.) all have to be replaced ... I stopped using RO water a long time ago, just no sense in using something that 'incomplete' ... better off with spring water, or even tapwater ... also, you shouldn't be feeding every 3-4 days, (once per week, at 1/2 dosages) is much better, you could just be 'locking out' the phosphorous ... :smokin:

Great Troubleshooting Guide here: Revised: The Complete Guide To Sick Plants,pH and Pest Troubles - PlanetGanja.com
the image reaper Reviewed by the image reaper on . Purple stems : ) E-indoor E-soil + coco 50 / 50 SCL-Anything you have added to the soil E-Charcoal filtered water E-Source water pH 7 E-Age of plant 4-5 weeks from seed E-fertilizer Advanced nutriens, grow micro bloom (1/2/3 or 1/2/4) big bud mother earth, B52 E-Rate of application 1 feeding every 3 -2 waterings E-Air temperature 24/20 Celcium 75.2/ 68 farenheit HD-Reservoir temperature 20 celcium / 68 farenheit Rating: 5