I'm interested in doing an ecosphere, but don't really have access to a pond or similar. Is there something I can get online that will thrive without any outside help?

>>5017302 (OP)
You could order live Daphnia from an aquarium store. They're commonly used as fish food and really effortless to keep.

Ordering fairy shrimp eggs and raising them could also work. Once there's some algae growing in the sphere they should also become pretty self-sufficient.

>>5017302 (OP)
If you leave a large tub of water filled with leaves and rocks outside for long enough it will get colonised by copepods and other inverts

>>5017302 (OP)
buy aquatic plants from the local fish store and you're guaranteed to get some hitchhikers like bladder snails and copepods

Pickle jar