It's been a about a month since my last post in this thread, so I thought I'd give a quick update.
As I've added fish, they've either eaten or out-competed the hydra that was infesting the tank last time I posted. There are some left, but even specifically looking for them I can only spot 5 or 6--which is a level that doesn't bother me at all.
On the negative side, I've had a bit of a staghorn(?) outbreak and it's taking a lot of work to keep it from infesting everything. I've raised the lights a bit and increased CO2 but I haven't had a lot of success in slowing growth. In this photo it looks pretty green, but I think that's just the color of the moss showing through. When I pull it out it's pretty gray.
I did a bunch of water testing today, and my nitrate was way down from the usual level; somewhere between 5 and 0ppm. I haven't increased my dosing level since my plant mass has doubled, so I wonder if that's part of the issue.
One of my rasboras kept getting in the way as I was trying to photograph the algae, so here's a snapshot. Of course when the camera appears the best-coloured ones are nowhere to be found, but what can you do?