Haze on aquarium glass

I kept meaning to ask everyone about this. Does anyone have a good technique for getting the haze off the dry part of the inside of your aquarium glass where water splashing from our filters? It’s almost like a chalky residue and even with a slightly more abrasive aquarium sponge I can’t get it all off. It reminds me of calcium or salt which is possible because I have crushed coral as a substrate. Obviously I don’t want to use any chemicals. Any suggestions? It doesn’t hurt anything but I like my tank to look clean and have a clear view of the turtles. -Scott