Most people are generally not equipped for large algae treatments. I see guys treat 1 acre ponds choked with FA with small 10 gallon Fimco's or Solo backpacks. Granulars can help by transporting the product to the algae on the bottom but floating algae not so well. I have seen Tilapia work but not in all cases. It's good to try Tilapia and see if it helps.

Getting proper mixing is very important. The general rule of thumb is to mix one gallon of product to 9 gallons of water with appropriate surfactant. This allows the product to move easier in the water column. Starting early in the spring on the pond is crucial to keeping the biomass down to a minimum. In ponds that get the tough algae species like Hydrodictyon and Pithophora you need to be on your game. Keep your pond dyed all summer. My applicators usually chose black dye but most of my clients refuse to let their ponds look like the Masters so we stick with blue. Just sprinkling some algaecide on the top of a large mass of algae will more than likely kill or burn the top layer. The undermass will likely resurface soon after treatment(Remember 9 to 1). Boat wake will also help break apart the mats to allow for a better treatment. If the algae takes over most of your pond just treat in weekly sections until you get caught up. Also don't be afraid to try other products on the market. We use beneficial pond bacterias on our smaller ponds which has proven successful in most cases.