I have a blue hippo, purple, and a chevron tang in my tank and they all seem to get along well. The question was about blue hippos which they can be some work especially if they get ich as mine did. I had to treat mine three times but now is mostly resolved, I feel the trick is getting a healthy fish from the store and one that is more mature. Mine was very small when I purchased it and at that size they are very prone to stress which means ich infestation. But after all those rpoblems it is one of my favs.