No, a German blue ram isn’t aggressive. Unlike other cichlids, German blue rams are quite peaceful. They can also get along well with other species, making them an excellent addition to a community tank.
However, German blue rams still have a feisty side that rears its head during mating season. A German blue ram can still be somewhat aggressive when protecting its mate and offspring.
Additionally, this fish is very protective when it comes to its territory. German blue rams won’t hesitate to attack other fish encroaching on their territory, especially when the tank is particularly cramped or overcrowded.