Ventilation and Humidity:
Unfortunately, I still don't have a ventilation system, so the humidity is only at 60%. The German weather has been helpful this week, as it has been raining. I've kept the window open, which has been sufficient for now. The plants don't seem to mind the current conditions.
Watering and Transplanting:
I transplanted the plants a bit prematurely and then overwatered them. As a result, I had to let them dry out for a week. Fortunately, there was no mold, which is a relief. It's been years since I've done this, so I've forgotten a few minor details. Nevertheless, the plants survived.
Nutrients and pH Levels:
Still no fertilizer, just pH-adjusted water. The plants are doing well under these conditions.