Want to thank everyone again. The driftwood made an almost immediate difference in the tank -- the shark LOVES it, and only occasionally pesters the smaller fish now -- it came with snail eggs on it (it was in a tank at the store) so now there are snails! All the fish now get their fair share of food, so I'm not overfeeding anymore, parameters are stable, my algae issue is resolved (I was exposing the tank to too much sunlight) and I have four species of plants in there that look way better than the plastic ones, and are quite clearly helping stabilize the mini-ecosystem in there. The shark likes to eat the duckweed, though I can see I'll have to clear that out periodically as it's alreadsy covering almost the entire top of the tank. As soon as I get a little free time, I'm going to build up the schools of serpae tetra and zebrafish, get more plants and another peice of driftwood. They only had "medium" sized peices, and I'd like one that goes higher in the tank.
The RTBS is amazing. He's visibly grown larger over the course of less than two months. The little guys both now come hang out everytime I approach the tank, though the shark is rather aloof, and spends most of his time behind the driftwood. I'll post another pic when I get a minute.