Your pond doesn’t need to reach the boiling point or feel too hot to you in order to cause stress or irreparable harm to your pond life. In fact, the temperature might feel darn pleasurable to you as you dip your toes into it after a long day of work. Once the water temperature rises above 80 Fº, you may have problems.
Your fish might appear stressed out, gasping for air close to the water’s surface or especially close to a fountain or waterfall.
Warm water has a low capacity for holding oxygen, while cooler water can hold gigantic amounts of oxygen. Warm water and increased activity go hand and hand, and that increased activity means the fish require more oxygen when less oxygen is available, thus creating a vicious cycle. Stressed fish often begin to develop diseases, and soon enough you’ll have a domino effect.
