KALKWASSER MIX provides bio-available calcium for lush growth of purple pink and green calcareous algaes snails hard tube worms and clams. Corals will open more and stay attached to their skeletons better with regular use. Phosphate and nitrate free! Contains no gluconates EDTA or other organics to raise DOC levels as many competing products do. This product is the original European Method that has never been equaled for calcium addition to a Reef System! It will provide long term results that no other supplement will! and#149; It requires a little more work but so does anything that is really worthwhile! KALKWASSER MIX can be used with Kent Marine Concentrated Liquid Calcium or TURBOand#149;CALCIUM for maximum results. Strontium addition via use of Kent Marine Strontium and Molybdenum Supplement or TURBOand#149;STRONTIUM is absolutely necessary as well. Use of Coraland#149;Vite and Essential Elements are beneficial as well.