Whenever you set up a new aquarium, or add new fish to an existing aquarium, make sure you know what each species of fish prefer for water temperatures. Cold-water fish, such as Goldfish, should not be kept with warm-water fish, such as the Betta. Even though they may get along, one or the other will be at an uncomfortable temperature. To ensure your fish are happy and healthy, make sure you choose fish species with similar temperature needs, provide heat for your aquarium as needed, and monitor the temperature with an aquarium thermometer.
Photo © Shirlie L Sharpe