Red Sea Coral Pro Salt, 175 gal. Mix. **** PRODUCT MANUAL **** Coral Pro Salt has been specifically formulated for use with reverse osmosis, or soft tap water and contains the elevated levels of calcium and buffer capacity that provide the extended availability of these elements, essential for vibrant coral growth. The Coral Pro Salt contains no Nitrates or Phosphates, and reaches a stable, natural pH shortly after mixing. The Coral Pro formula provides elevated levels of calcium at the “lower than natural” salinities preferred in reef aquariums. Treats 175 gallons.