RiverRat...Check your TDS....When water evaporates the only thing that evaporates is pure h2o. All the disolved solids that are in the water stay in the water. Over time they will cause scaling, staining and cloudy water.
In Palm Springs like Havasu we can lose 8- 10 feet of water a year due to evaporation. Basically we lose a pool volume of water every year.
nope haven't had that checked but let the sun burn off the chlorine. Just keep a very low dosage of chemicals in it during the winter months. Haven't had any problems. Water is still sparkling clear.