I am starting to think that there might be some aggression in my top 40 gallon aquarium. I have 1 common pleco, 1 rhino pleco (if I remember correctly) and 3 electric blue haps. I went in there to check on them tonight and the rhino pleco was swimming around the tank fast and all of the haps were really dark blue. Usually only one or two are really that blue. When I went in there all 3 were blue. I didn't see what exactly happened, but the fish look ok. What should I do?