Several threads have pooped on it, but it looks like it was determined they had a quality control issue for a little while that was causing problems with sand size. Has that been resolved, or is it still an issue?
i have been using quickrete for 3 years with no issues. some sand will always come through the laterals. its the nature of the material and how its screened.
what makes pool filter sand pool filter sand is that its fractured. this creates sharp edges that allow it to pack together more closely. Masonry sand is round from being tumbled in the river. it can filter, but not as well as the sand with sharp edges.