My impression of the sand is that it is of lower density. Which only means it weighs less than regular sand. You shouldn't have half the "amount" in the filter. The level of sand should be the same as if it was regular sand.
As another suggested, bump your chlorine up a few ppm's over shock level. That way, you won't fall below minimum shock level when you do lose chlorine between dosings. And especially overnight or if you can't be around to re-dose.
As another suggested, bump your chlorine up a few ppm's over shock level. That way, you won't fall below minimum shock level when you do lose chlorine between dosings. And especially overnight or if you can't be around to re-dose.