Algatec provides superior cleanup especially in chlorine and salt pools due to its strong killing action with all types of chlorine products. The product is both an algaecide and algastat (prevents re-growth). Algatec also eradicates Black Algae (fungi) with chlorine in just 7 to 10 days. Unlike phosphate remover products that seek to control algae by phosphate starving, Algatec kills algae and prevents its re-growth. This amazing product makes it easy to control algae blooms and leaves pool water sparkling clear.