Over-watering is watering too frequently, as opposed to giving too much water at once. You're in an amended peat mix. Watering every two or even three days is too frequent. Your plants are showing signs of chronic over-watering. If they were mine, I would let the pots dry back until I saw straight-down droop in the lowers. Then I would water to saturation, and dry back until the pots were very light. I've never run Plagron Light Mix, but in similar amended peat mixes, correct watering has required between a quarter and a third of the media volume. Lots of ways to grow. That's just what has worked for me.