ABC6 welcome to the PB forum . What is the alkalinity and the water temp. Unless the alkalinity is high enough and also the water temp. you will not see the bloom you want. Our bloom starts around May of each year. Read about it here :

http://msucares.com/pubs/publications/p1428.htm

http://msucares.com/wildfish/fisheries/farmpond/management/fertilization.html