Caribsea bulk sand are bags of sand that have been damaged in transport, or have been re-packaged. This is the exact same sand as the regular caribsea, just not in pretty packaging. Limited quantities available.
1 - 1.7 mm diameter grain size.
A revolution in reef keeping! This is the one you've been reading about in all the hobbyist publications.
This grade of aragonite is specifically engineered for plenum type nitrate reducing beds.
The pore water space created by precision grading also allows maximum pH support and dissolution of calcium carbonate.