I have never had veins, I have never air locked it either, Kombucha unlike beer thrives on wild yeast and leaving it uncovered is normal practice. I ferment at 65-70 because that is how cold my home is living in Alaska in the winter. Ideal temperature should be 70 - 80 F. How thick is your film on top? and what color?
"Are you going to be working on your brew stuff? Yes honey I am going to be working on my brew stuff."