What is the potential energy savings for each degree you lower an indoor pools water temperature?

"Every 1 degree reduction can cut your energy usage by between 5 and 10 percent. Once you have lowered the thermostat, keep the remaining heat from escaping by using a pool

cover when the pool is not in use." This is according to a NREL publication: http://www.nrel.gov/docs/fy00osti/28038.pdf. Note: It doesn't specify between an indoor and an outdoor pool, but it does have lots of other good energy saving tips.