One of the questions I am often asked is, “How much water does a pool cover save”? We all know that pool covers save water by virtually eliminating evaporation when they’re on the pool, but how much evaporation does your pool have? It’s a valid question, and the answers can vary quite dramatically, depending on several different factors.It would be perfectly normal for an ‘average’ sized pool to lose anywhere between 2mm and 10mm of water to evaporation every day. Location, wind speed, humidity, shade, sunlight, air temperature and water temperature all have an impact on evaporation rates, and so does the size of your pool, so there really is no ‘average’ answer.