Woot. It's tomorrow, and I went out and found what I was looking for: There was a little expansion pack for those fake rock shelf thingers, and I got that, so could not force the one on the right side to oddly balance on the arch rock. I also added: 7 fish (Rosy red goldfish), the 6 fake plants, a live plant (right side), and a special basking ramp (center). So now the guy has three places to go to bask, and a number of places to hide, swim through, etc.. I think it looks pretty good now.