Now dont ask me why as As I have been told and read that the old 20-20-5 pond fert is not as effective as some of the new water soluable and liquid fert but I can say this. For about 2 years I have had dificulty establishing a bloom so after much thought I went back to the old 20-20-5 granular and with in 4 days have the nicest bloom you could ask for. I thought the newer fert would be cost effective but not the case for me as I have spent about $400 over 2 years on fertilizers that failed to work. As goes the old saying if it aint broke dont fix it. So with that said to those of you that may also be having trouble establishing a bloom go back and try the old 20-20-5. Of course your alkalinity needs to be above 20 ppm. I am keeping it up by adding 150 # of hydrated lime about every 6 weeks. I have added 30 tons of ag lime over the past 4 years and could not get it above about 16 but the hydrated does the trick for me. I guess all ponds are different you just have to figure what make yours work.