The plot thickens: I was looking at the Badgerling's betta tank, which is planted with the same batch of clover fern. Hers has converted to its submersed form (carpeting, teardrop-shaped leaves) and is growing well. Mine put out a bunch of tiny, stunted-looking, clover-shaped leaves, then stopped growing. I think somehow the fern in my tank doesn't realize it's submersed yet. Just my luck to get all the plants in the remedial class...
The copepods are fun to watch. I have a couple of pond snails that look pretty healthy, too. Really need the plants to start growing so I can add some fish to this thing, though.