Hey there, bro! 👋 The reddish leaf stem indicates a phosphorus deficiency. A phosphorus deficiency can occur due to a lack of phosphorus in regular watering or because an excess of nitrogen blocks phosphorus absorption. You're not in a critical situation, there's no danger to the plant. Stick to your feeding schedule, but don't overdo it with nitrogen (N), as it can worsen the phosphorus deficiency a bit. 👌😇👍 Good luck, bro! 👋