Sad,
The algae that is "good" to have is phytoplankton, - the microscopic plants that are to small to be seen as individuals, but when present in sufficient numbers give the pond water a nice green tint. This is what is refered to on the forum as an "algae bloom."
If the "algae" that you are trying to get rid of is visible to your eye as hairy, stringy globs... that isn't phytoplankton. In fact, an algae bloom of phytoplankton, - since it tints the water and limits the penetration of sunlight to the lower depths, can help reduce the growth of the "algae" that you are targeting to remove. Nutrient flow into the water, suspended sediment in the water, the chemical composition of the pond's water, muck on the bottom of the pond, aeration and circulation... all of these factors play a part in the growth (or lack there of) of the types of "algae" in your particular body of water.
You may want to snap a picture of the "algae" that plagues you and get some advice from the pros on this board. They've helped me out a ton.
