DTs can be used to start a culture, but because it's not a mono culture you can get unpredictable results. Diversity is very good in your tank of course, but its not so good for making viable, sturdy cultures.
Namely: DT-based cultures can crash quite easily. One species will outcompete the others, and eat all of the food before they can. The other starving species then die, which fouls the water, and then kills the top species too.
It's really not that much more expensive to order a monoculture from an aquaculture place, and you'll have a much more certain chance of success. Most people that succeed in culturing keep the different species that they use in separate cultures.
Note that non-photo species tend to thrive best only in very large systems: they are demanding both because they need so much food, but also such good water quality, which are two things that are very hard to balance in a very small water volume. You're taking on a real challenge!