I'm sorry, I know you guys want to help but the language barrier is too much for me so it's difficult to understand. The reason why I went to this forum to ask is because there are no correct instructions on how to regulate heat or even keep ball python in Dutch (there are a few, but usually they are from pet shops which means that half of the information there is just untrue - like they tell you that ball python should be kept with multiple others and that the temperature should never be higher than 20 degrees).

I'll just ask some more at reptile shops instead, but thank you for trying to help. Apart from the tank trouble though, my ball python is a true angel and I am impressed by how gentle he is.