I have a 0.4 acre pond that I added an areator to this summer (1100 gph) to increase the oxygen content. It runs about 8 hours per day. I also added the blue dye to help control algae and water plants. It seemed to help. However, now the blue is gone, I'm getting brown algae on the bottom (may have been there all along) and surface algae is beginning to take over again. Should the blue dye be used year round? What can I do to help control the surface algae? The pond is stocked with fish.