I always say it, if you want to understand Algriculture you have to go ask someone who has a Degree in Algriculture. Asking people who have no engineering experience in that field will get you nothing but people guessing and giving you 50 different answers, who do you believe? Exactly, u don't know who is correct and who is false. First off, It's never genetics and if anyone ever say that again get far away from them. Purple Hard Stems is never a genetics trait. Go outside where it grows naturally and find one, it doesn't exist.
Now, purple hard stems is a result of a few things happening simultaneously. It's a result of stress from TO MUCH LIGHT, to high of ppdf or umols/m2. The plant can't photosynthesis all that light. Lets go back to its roots and let's evaluate this the correct way directly from a Master Engineer. A cannabis plant uses light, water and co2 then converts it into sugar and oxygen as waste. It stores the sugar for 12 hours then uses it when lights out. It's like carbohydrates for plants. Cannabis plants are phototrophic, meaning it can create its own organic nutrition unlike humans, we get ours from food, our bodies can't create calories and protein on its own. LED lights are very intense unlike natural sunlight at 1500 ppfd the plant does not struggle like 1500 ppfd of light indoor. Natural sunlight and the environment is much absorbing outdoors than indoors and there is no reflection on sunlight and the sun rotates, it's not fixed. When light is fixed it beams one direction 18 hours, it's to much. Plus the added reflection from the mylar tents, its to much. Outside the light goes back to the atmosphere, indoors the light goes left right back to the plant, its to much. The plant has no choice but to photosynthesis all that light, it runs out of Magnesium very fast. Magnesium is the center molecule that builds cloroplast in chlorophyll,
magnesium is the center atom. That's why it's always the first to run out, purple is mag deficiency. Adding Magnesium will not fix it if it's depleting from to much light. It can't build cloroplast fast enough to keep up with Chlorophyll production as mag is deplete. This causes the plant to heat stroke itself and the stems turn hard as a slow growth factor. It's protecting itself. To stop this get a ppfd meter and stay under 375 ppfd in Veg and under 700 in flower without Co2 supplement.
