propagator growing

[petlor]

I have just started on my new top ten electic propagator having sown the seeds the inside of the top cover of the small modules is very wet do i open the small vent or leave them as they are. This method is all new to me any help would be appreciated / ,the propagator runs at about constant 16 degrees and all the modules are on top of the heated tray

[Bigmallly]

I leave the vents closed until the seedlings show through, then open the vent. Once the seedlings are established, take the lid off.

[Two_Sheds]

I open the vents if it gets steamy inside: I don't want moulds or compost gnats

[petlor]

Thanks for replies, seedlings just starting to show will open vents and see how they go