Once you have opened the box and are ready to introduce them into your hatchery water, it is critical that you temper the eggs into your water. Tempering means to gradually bring the temperature of the eggs up to match the incubation temperature of your hatchery. The eggs will arrive on ice at a temperature of +/- 4°C (39.2°F), and it is recommended that you increase the temperature of the eggs as slowly as 2°C each hour. Various methods can be used for this process. For more information on various tempering methods, please see the link in the Relevant Info box to the right.