Sarah's design for her farm is based on eel farms in she even had some dutch fish farm engineers building things out when we visited. She keeps the water at a lovely warm, consistent temperature, round about 70 to 75 degrees. In the wild, when the water gets down to 50 degrees or below, eels stop eating and just kind of hang out in the murky bottom until spring. But american unagi eels eat all year round, so they reach a harvestable size between only seven months and two years.