I'm trying to seed springs in tank established already with frogs in it, and came up with what I think is a reasonable solution. Works for me at least.
I've got just a small but thriving culture, only have scraps of corkbark on top of the soil for cover. Removing the corkbark and shaking them off works mediocre - not consistant enough for me. The springs run for cover instead of sticking to the bark. (Most people use lava-rock for this method - but I haven't got any so I tried the bark.)
I hesitated to use the method of creating a pool of water in the culture and sucking the water and floating springs out because I didn't want to oversaturate the soil. (My culture is small - no room for a isolated swimming pool for springs.)
I thought I'd try an experiment and its working pretty good. I made a sealed cone from coffee filter, a couple inches tall. Put a tiny pinch of the springs soil in it (the springs will NOT go in the cone without soil to hide in)with a much greater amount of spring food. Leave in the culture overnight, and the next day the cone has got plenty of springs feeding on the food. Open your viv, find a spot to deposit about a thumbprint size cone of soil, pull out the coffee filter cone and dump it in.
I got this idea because when I open a spring culture they tend to dive into the substrate, not jump out. The cone works because when you open the culture the springs hide downward in the soil there instead of escaping out of the cone. It seems to work perfectly for me, and, the resulting spring/soil/food pile has shown to be a very attractive feeding site for days after I put it in. The first day or two my frogs just formed a circle around the pile... waiting. I'm just hoping that enough springs survive and continue to seed the tank.
Added benefit is this adds some spring food into the viv for the colony that (I hope) is doing their own thing in it. The small amount of soil you add to the viv is so little that over a couple days the humidty and spraying just melt it down into the substrate.
Jay