Quote Originally Posted by milynor
At some point every year I have developed a black algae problem....
I think an extra dose of 60% polywhatever would be a better defense than the Natures 2. When I built my pool, I threw away the $100 and installed one. Then I got wise, cut it out, and gave it away. Instead of looking for another solution, try to determine a pattern or time when you get the algae and maybe increase your testing and or FC. The dolphin should definately help also. Take Carls advice, Stay Ahead...