Temperature

• Cues from the environment can help pond fish breed spontaneously, so the temperature of the pond should be approximately 74 F, or 23 C, to increase the probability of spawning.
  
  

Season

• Most pond fish will breed during the spring months and the early summer months. Females will be swollen with eggs and will seem particularly interested in the pond's plant life.
  
  

Plant Life

• With plant life in your pond, fish will be more motivated to breed, so make sure to include numerous plant species with different plant textures that offer plenty of hiding places.
  
  

Egg Media

• Pond fish eggs need a special place to hatch in order to increase their likelihood of survival. Providing egg media also ensures a greater likelihood that pond fish will breed.
  
  

Behavior

• A female fish that is full of eggs swims more frantically, especially through plant life. Koi are far more obvious, as male fish harass females to coax them into expelling their eggs.