I have a single, fairly agressive angel in a 55. Tankmates include black neons, platies, cories, a syno and temperarily a few apistos. It used to have long fin danios but Halo (the angel) seemed to have picked them off one by one. I added the black neons as replacements and they seem quick enough to not get picked on. What I'm wondering is whether a filtering shrimp such as a bamboo or green lace shrimp could coexist with such an angel.