Well, it seems that the plant I thought was Elodea is actually Hornwort (Ceratophyllum demersum), commonly known as “Coon’s Tail” because of its appearance.

A tip of the cap to the hobbyists at Aquatic Plant Central for helping with the I.D.

The darn thing grows really well; in the wild it’s eaten by fish and ducks. But in contained environments, it can grow to the point where it crowds out other plants – unless you trim it regularly. Well, so much for a maintenance-free jar.

Since trimming it will take nutrients out of the jar, I’m a bit worried. I don’t want to have to worry about resource depletion. Maybe I’ll save the trimmings, dry them out, burn them, and put the ashes back in. Or, since I found an old wine carafe (with lid!) that has a much greater capacity than the jar, maybe I’ll just get more pond muck and water (and critters, hopefully) and dump everything into the carafe.

By the way, I did see three diving beetles moving around yesterday. Seems they are most active in the evenings. There are also quite a few snails of differing sizes.