Powder algaecides containing mineral salts will not remove black algae. Only O.A.C. products with the correct carbon chain length will remove and penetrate into the spores, thus preventing re-growth. Again, ensure the pH is between 7.0 and 7.2.
AlgiHalt is one of the most powerful and effective black algae removers on the market.
AlgiHalt contains 500gr/ltr. active compound and, is reasonably safe to use, it does not cause dermatitic reactions should the concentrate get in contact with skin. As AlgiHalt has a strong detergent base the skin will tend to dry out if the concentrate is not removed with water from the hands. Foam is a natural by product of AlgiHalt, but will gradually disappear as the product attaches itself to the pool surfaces. If infestation of black algae is considerable, a second bottle will be required.