What does it mean if goldfish constantly swim?

How to remove salt buildup from concrete fountains? Is there piranhas in Perth? What are some types of fish that are affordable to take care of dont need a heater and will stay alive for a good amount of time with good care? How does pygmy seahorse skin adapt to the coral around them? Why is your male guppy twirling upside down and to its side and still alive? Why are my Fish floating at the top and gasping for air? What other fish can live in the same tank with a puffer fish? What is the correct name for animals that eat fish only? What do baby trout eat? How do you feed a leaf scorpion fish? Is the Nile Perch edible? What is the difference between a dorsal fin and other fins? What is the french word for the fish marlin? When pufferfish evolve? Can sharks smell blood if not in the water? Are sharks the oldest animals ever? What can a star fish regrow if it loses one? What is the difference between a sand shark and a dogfish? What are manta rays classified as? The nearest place to get reverse osmosis RO water for my marine aquarium is 1 hours drive away you cant do that every week are there any alternatives?