Listless goldfish

Question
Yesterday I moved a goldfish from a one gallon bowl to a 10 gallon tank. I also
added another goldfish. Initially both fish seemed fine and ate well. However,
today the original fish has spent the day lying on the bottom of the tank with it's
fins down hiding behind a clam shell. Is there something wrong with the
goldfish? Is there anything I should do for it?

Answer
A ten gallon tank is too small for even one goldfish, much less two. Please return your other goldfish, and work on getting a 20 gallon for the other one. Once he is in a cycled, clean, dechlorinated tank with decor for privacy and gets settled, he will be a healthy, happy fish.