this is what i would do. i would go out and buy some play sand. then just use live sand over the play sand. just play sand wont look that good.
but when you want to use play sand or any other type you need a do a venegar test. I believe you take a handfull of the salt and put some venegar on it, if it sizzles then the sand is good to use. if it doesnt then dont use it.