so I know I'm late, but you do need springtails too they're very beneficial if you want to catch them the best way is with this trap
take a small deli container peel off the 3 micron filter on a vented lid put a wet paper towl in the bottom then put a couple peaces of any store bought mushroom put the lid back on without the 3 micron filter and take it to the spot you found the springs place the container on the ground and cover with some leaf litter in you yard the wait a few days.
Now for Isopods they're very easy to catch just cut a potato in half hollow out the inside of both put in a few leaves then put a rubber band over it to keep it together, wait a couple days and some should be in there
Also, please don't put them in straight away keep them in a container (Provided down below on the best proper setup) for a few weeks maybe 3 just so they can all breed become more established and get out any toxins they may have had before you took them in.
Springtails: get a large tall container fill it up with about 1 inch of water then feel it up half way with a charcoal chunks. Springtails love charcoal they love to hang around it reproduce on it etc.
Feed them grains of un-cooked rice they don't actually eat the rice itself but the mold that grows on the rice (They eat mold which is why you want them in your enclosure)
Isopods: Get a container fill it up with your enclosures substrate then put them in, feed them potatoes and leaves.