I think it was time to transplant to bigger pots, because I saw roots coming out the bottom of the tiny ones (probably because there aren't enough nutrients in the universal soil?)
I only get morning sun, so I take the plants out every day to my balcony.
The rest of the time, they are under plastic domes and lit by a Philips Hue Lightstrip converted to be a ghetto quantum LED board.
I only watered them after replanting, with Brita filtered water and tap water that I've left to sit for days.
I've given Blue goo #1 to a friend, so it won't make any more appearances in the diary.