There will be no stagnant water dear friend. The water is constantly renewed from the spring. The pool will stay around 48-50 degrees Fahrenheit (8.8-10 degrees Celsius)....we will probably run an auxiliary line from the reservoir to a refrigerator house....but that's some years down the road. My next post shows such a line as it runs through the dam. In the old days our ancestors would use springs as a form of refrigeration....and it's free.