I must disagree. Phosphates only feed algae if it's alive. Kill it, keep it dead, and keep your chlorine levels up so it stays dead and there won't be anything to eat the phosphates.

Phosphate removers should not be used until other methods are no longer able to work. I see no reason to expect our simple bleach method not to work--just because some pool store clerk wants to sell Melba phosphate remover.

Use MWSmith2's free, downloadable Bleach calculator to compute how much bleach you need.

Or remember that 1 gallon of regular bleach (5.25%) adds 5.25ppm to 10,000 gallons of water. 1 gallon of ultra bleach (6%) adds 6ppm to 10,000 gallons. Adjust your bleach based on that, how many gallons you have, and how high you are pushing your FC level.