I would call Diamond Brite and ask them . . . and then ask if you can record their statement that this is "normal" if they say it is.
http://www.sgm.cc/diamondbrite/index.html

If they won't say it's normal, for the record, then you've got your answer.

Personally, I have no idea; I've never even seen a pool with the stuff, though I know there are some in this area.