Axolotls live at temperatures of 14 °C (57 °F)-20 °C (68 °F), preferably 17 °C (63 °F)-18 °C (64 °F). As for all cold-blooded organisms, lower temperatures result in slower metabolism; higher temperatures can lead to stress and increased appetite. Chlorine, commonly added to tapwater, is harmful to axolotls. A single typical axolotl typically requires a 10-US-gallon (38 l; 8.3 imp gal) tank with around 150 millilitres (5.3 imp fl oz; 5.1 US fl oz) of water. Axolotls spend a majority of the time at the bottom of the tank.