I was given a couple of fish a few months ago with a tank that someone didnt want anymore. One of the fish is a Siamese Algae Eater and I have read that they are friendly, community fish but if they are left on their own without any other Siamese Algae Eaters to school with they can become aggressive. I also have a couple of Zebra Danio and 3 Red Cherry shrimp in the tank. He is the only Siamese Algae eater in the tank and he has become very territorial and aggressive when ever the othe fish go near him, He also killed one of the Cherry Shrimp. I am wondering if I was to add another Siamese Algae Eater it would improve his behaviour and become less aggressive because he would have other fish to school with or would it make it worse because he has already become very territorial? Any help or advice would be greatly appreciated, thanks!