Water Soluble Source For Calcium. Used in spring and fall to strength flower stems, psuedobulbs, and leaves. Helps prevent black rot of new growth and weak flower stems in spring. 15.5% Nitrogen source, 14.50% Nitrate Nitrogen , 1% Ammoniacal Nitrogen. Calcium source is 19.0% soluble Calcium. 1 Tbs. per gallon.