I was able to identify the problem why the Bluedream grows so poorly. Some leaves had covered the substrate and mould had developed there.
I removed these leaves, loosened up the substrate and installed another fan. It actually took 7 days for the pot to become noticeably lighter, it was practically standing in water and hardly any air was getting to the roots.
The switch to flowering fertiliser also came too late. So all mistakes on my side that were caused by too much watering.
Nevertheless, they are continuing to develop well and I hope the end result will be reasonably satisfactory.
@Hempface86, Yes, I know, but I have to get the tent free for the next grow. Then I also have a short vacation coming up. A big update will follow tomorrow!
@NamasteDave, Hey thanks for your comment! I'll follow your Grow too, I'm curious to see how it develops for you.
I'm already in LST, but I'll tell you more about that in the next update.
@Hempface86, thank you! I'm very excited to see how the growth will be, as this grow has significantly more surface area and the plants can grow 1.4m high.