It depends on the salt. A salt like calcium carbonate is going to react to an acid but salts like calcium chloride isn't going to react with many acids. Keep in mind that an acid may not get into the pores in the glass to remove the deposits. You can polish the hazing out, but it takes some effort.The coloration is white which lead me to believe it's some kind of calcium deposit. It started our rather thick and you could break it off by hand, it's the final thin layers in the crevices that I can’t seem to get to. I'll break some off another tank and drop in acid for etching concrete floors. If its lime based it should bubble up. It looks a lot like salt wicking at first. What would the salt do in acid? It's not on the glass, but I have another tank I intend on using as a plant nursery that does appear to be etched.
Thanks for all the good advice.