How To Prevent Evaporation In Aquarium. Keeping the ac on really helps too. By keeping fish adapted to cold water, you can significantly reduce evaporation.
After 2 days there will be no mere presence of chlorine in any water. It will not be possible to completely stop evaporation from a saltwater aquarium but the best thing you can do is to add a tank cover. Add aquatic plants that will partially cover the water surface to your pond.