10,000 gallon concrete pool, 15x30. Just had a 36" spillway installed, sheer descent about 2 1/2 feet. I ran the waterfall for about 11 hours overnight and lost about an inch of water. Contractor is telling me this is normal evaporation. Turned off the waterfall and lost no water the next day. Question: what is your experience with evaporation due to the use of a sheer descent water feature?
