Koi Pond Heater FAQ

What do you recommend as the optimum water temperature for Koi year round?
In the summer growing season it is best to keep Koi between 74*- 82* in order to be able to feed high protein (growth) food. This is when the Koi's immune and digestive systems are at their peak performance. When temperatures rise above 82°, it is best to reduce the amount of food and to start feeding with a wheat germ based Koi food to reduce the protein content they ingest. The Koi are still able eat protein at these temperatures,  but they will not metabolize it very well.

Fall temps should be kept between 52°-60°, feed a wheat germ based, low protein food.

Winter temp should be kept 45°- 48° or above 55°. Even though a Koi's immune system is in weakened state in the 49°- 55° range, the Aeromonas bacteria is still active enough to cause them harm. If you are able to drop the Koi down to this temp (45°- 48°), it is important to not feed the Koi during this time, it is their winter fast period. Another important thing is to minimize temp swings 8°- 10° to not stress your Koi, you may not be able to do this where you live do to temp swings during the day. The average winter fasting period averages 1 month, some people do 2 weeks others do a lengthy 6 week fast. This helps the Koi reduce their seasonal fat storage and serves to improve their body conformation. In MN winter fasts are an average of 2 months due to our cold weather. Spring season it is important do bring up temps up to 60*- 65* to bring their immune & digestive systems back to par.

Where should I check the temperature in my pond to make sure the heater is operating properly?
I would check in two to three different locations to get an average water temperature. At the farm we use the infrared temp guns, as we have 8 -12 systems we monitor daily. Thermometers that sit in the pond will get coated in algae and need to be cleaned often.



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