As a FYI about the quickcrete, Yeah, there were a couple of reports about it being bad.
Dave had a conversation on the phone with the quickcrete rep. It appears as if a bad batch of Pool Sand did get distributed, but overall, they have a good quality procedure and there should be no reason to avoid it, unless you just want to be ultra safe.
Pool Sand is #20 silica. Anything smaller than #20 will get through the holes in the laterals and end up on the pool floor.