human
How can I tell if the fish in my aquarium are healthy?
assistant
The best way to tell if your fish are healthy is by observing their behavior. Look for signs of stress such as erratic swimming, changes in appetite, or abnormal coloration. Additionally, you should check the water parameters of your aquarium and make sure they are within the range recommended for that species. Finally, take a sample of your fish's droppings and examine them under a microscope for any abnormalities.