Well, apparently hackers don't have green thumbs. At least I don't. Managed to kill the two plants, and this time I know exactly what went wrong. Quick recap of the losses:
1. Water too hot? Plants die. 4 victims.
2. Too much fertilizer? Plants die. 2 victims + heavy casualties in the outdoor garden.
3. Cut the plant off too soon? Plants start to droop. 1 victim in ER, recovering.
4. Just pure clean water? Plants are thriving!
Things I learned: The water cooler works fine. However, I should stop using fertilizer for the moment, and look for better fertilizer, because the junk I have works fine on the peppers, but causes the strawberries to go evil. Some websites recommended cleaning the tank with a solution of bleach. I don't use bleach, in fact I dislike using bleach. So I went for something I used when I was in university and the dorm guys made a mess out of the plans: ChemiPro Oxi. Its used by home-brew beer brewers to clean their tanks, and its supposed to be "food-safe". Cleaned out the pipesystem, cleaned the complete tank (which was a mess of brown goo) and made sure that there was no junk left.
The lower right plant was planted last week, the others were planted yesterday. Note the one on the bottom left, that one was having issues before I planted it in here, now it seemed to pop up its head.