There was some good discussion about more complicated situations in this thread: https://forum.inaturalist.org/t/long-term-observation-of-a-pond-water-community-casual-or-not/11381/20
I once took a jar of water and leaf litter and debris from a vernal pool and watched it at home for a few weeks. I could find and photograph most of the organisms immediately after the dust settled so this question didn’t make much difference. But after a few days the aquatic isopods died and a parasitic worm came out of one of them. The worm was in the vernal pool and that might be interesting information to someone (a researcher was interested in a hydra from the same jar), but it was only the artificial conditions that enabled me to see it. 