I have a 55 gallon freshwater tank with lots of plants and these fish: 6 serpae tetras, 8 cardinal tetras, 6 rummy nose rasboras, 2 platies, 1 danio, 1 kribensis and 1 brittlenose pleco. I don't want another kribensis, platy, or danio. I was thinking of adding 7 Albino Cory Cats. What other bottom feeders could I add? What about some other fish? Top dwellers? Other schooling fish? Or maybe even a centerpiece to the tank? What are all of your thoughts. Thanks