I currently only have Leucs. I've kept aurotaenia, auratus, bicolor and imitator in the past
I add them as soon as I add substrate. New tanks have a break in cycle where things get moldy that often freaks out new hobbyists. Adding microfauna as soon as possible helps speed up this cycle as the microfauna feed on the mold. I personally keep a 5 gallon aquarium mostly full of ABG mix with a layer of leaf litter. There is a plastic bag laying over the top to hold humidity in. I mist it occasionally and stir the whole tank mixing leaf litter into the soil when I am ready to top it off with new dry leaf litter. It is basically a dwarf white isopod and springtail culture. When I set up a new vivarium, I use the ABG mix from this tank. This way my substrate doesn't need hydrated and I don't have to worry about adding microfauna. Plus I don't have to worry with keeping cultures of springtails and isopods going.Thank you so much for your advice. I've been reading the care sheets.
If I overlooked it, I apologize for repeating: when would the proper time to introduce microfauna be? How soon is too soon? I have springtails and dwarf white isopods.