@Peyopio, true though some do not see that as fun.
If you have negative pressure, you can balance that out by purchasing an intake fan that will suck fresh air into your tent. A small inline duct fan from Amazon + duct won't run you more than 20 EUR. You can even filter the intake so only fresh air comes in.
Partially correct. I live in Germany but I am not German.
@Spike_KCanG, Thanks! Yeah, a good part of the fun comes from observing, nurturing and problem solving I think…. Like today, I am building a wooden frame which will fit the sides, so the tent can expand a bit more. At the moment because of negative pressure in the box, the walls get sucked in and are smaller.
From your username I guess you are German? Is that right? 😊