Oxygen Deprivation
Goldfish need oxygen rich water. Hanging at the surface and gasping are symptoms of oxygen deprivation. This can prove fatal, so should be acted upon as soon as symptoms are seen.
Treatment
☆ Test Parameters. Nitrite poisoning can also cause oxygen deprivation. Ensure your water is piristine.
☆ Increase surface agitation, either by adding an airstone or adjusting your filter output so it creates lots of ripples on the surface. This increases surface area of the tank and increases gaseous exchange, where co2 comes out of the water and oxygen goes in.
☆ Perform a water change. This will replace the oxygen depleted water in the tank with oxygen rich water.
☆ If your tank is heated, gradually reduce the temperature. Warmer water holds less oxygen than cooler water.
☆ If your tank is warm, as the ambient room temperature is high, blow a fan across the surface of the water.
☆ Increase surface agitation, either by adding an airstone or adjusting your filter output so it creates lots of ripples on the surface. This increases surface area of the tank and increases gaseous exchange, where co2 comes out of the water and oxygen goes in.
☆ Perform a water change. This will replace the oxygen depleted water in the tank with oxygen rich water.
☆ If your tank is heated, gradually reduce the temperature. Warmer water holds less oxygen than cooler water.
☆ If your tank is warm, as the ambient room temperature is high, blow a fan across the surface of the water.