Two pool companies each told us different things. One said solar cover is to be on during the day when we are not using the pool because we will lose our chemicals and the water will eventually evaporate. Other pool company said to only put solar cover on at night or we could end up with a greenhouse problem (algae starting). What do we do??? We have kept it off completely, but now ( after a month ) have to add more water to the pool. Do we keep a solar cover on during the day or just at night????