Yes. The use of a solar (or other) cover SIGNIFICANTLY slows down chlorine loss. UV rays from sunlight are cut down a lot so the chlorine only gets used up by combining with organics (and there's less of that because less junk gets into the pool). In my covered pool, the chlorine usage is about 0.5 ppm FC per day at a level of around 3 ppm FC and that's at 88F water temperature.

Richard