I ordered a tropical springtail culture from Josh's frogs a while ago and the EXACT same experience you did. It took about a month or two for the culture to get going and I had to add an additional springtail culture that I bought from a board member. I believe the issue was that I had to few springtails in quite a large container. Anyway, eventually it will build up, but you're looking at a few months before the culture really gets booming. In retrospect, it probably would have been better to start the culture in something a lot smaller than a shoebox. But like I was, you're kinda stuck at this point.
Here are my recommendations...
1. Add another culture or two to your existing culture. Yeah, I know... it pissed me off too, but such is life. lol
2. Even though you have a lot of humidity in your culture, be sure to give the surface a good misting AFTER you sprinkle in some yeast. I've noticed that the springs devour it much faster this way. My culture will will eat two giant pinches of yeast in one day.
3. Keep the culture in a fairly dark and undisturbed area. Springs don't like to come to the surface to feed if there is too much light.
4. Don't feed them anything but yeast and you won't have any problems with mites.
5. When your culture is booming and you're trying to figure out how to get the spring out... Just take a leaf and sprinkle some yeast on it, then give it a light spray of water. In a few hours the leaf will be COVERED in springs for you to seed your vivs with.
Hope this helps! Good luck with everything!
