These animals do well in either a cool water aquarium or a warm water aquarium . They are compatible with many smaller less aggressive fish, except the Crayfish that are larger, more aggressive, and may bother small fish, but Crayfish are usually compatible with aggressive fish. Puffer Fish love to eat Crabs, Shrimps, and Crayfish, so they are not compatible with these Critters. Please get back to me. Parker Girl Reply.
All fish give off ammonia an other waste.
If the fish are not crowded and the aquarium has proper filtration, the ammonia and waste will not be a problem. Click here to read about aquarium filters. But for other reasons Goldfish are not compatible tank mates for Tropical Fish. For example, Goldfish prefer cool water and eat Goldfish Food. Click here for more details about keeping Goldfish in Cool Water Aquariums.