Effect not recognizable

I bought Tetra Pond AlgoFin especially against short-term infection of blue and filamentous algae. My UVC lamp was first turned out unnoticed. After correct dosage according hardly readable instructions, was not the slightest effect recognizable. Only changing the UVC-filter and the use of Holzum filamentous algae stop has eliminated my algae problem sustainably.
Due to the warm winter weather, I have now a little overdosed (must be yes and consumed in the summer that stuff brings nothing eh) at about 3 degrees water temperature in January 2014 tried the renewed deterioration (cyanobacteria) to fight. Even now in winter no effect is observed. Thus, for me, for the next few weeks to EVL. but once the winter weather sets in, put my filter system in summer mode. Tetra Pond AlgoFin can I therefore recommend at all.