I have a 55 gallon aquarium that is currently housing 4 juvenile angelfish, 5 platies, and 6 glofish danios. I have seen in the past few days that the angelfish are becoming more aggressive towards each other, the platies, and glofish danios. I am planning to relocate my platies and glofish to my 20 gallon neon tetra aquarium. What fish can I put in the 55 gallon with my 4 juvenile angelfish without being in danger?