Excital displaces red slime algae (Cyano sp.) by stimulating the growth of specific micro-organisms in light-sensitive places in the aquarium. Red slime algae will no longer have a chance. Safe for all aquarium residents and the biofilter. Important: Remove active carbon; all equipment may remain switched on. Add when aquarium lights are on for effective destruction of algae!. Dosage: for 5 days 10 ml per 40 litres per day. Visible results within 10 days. The first days time is needed for building up sufficient bacteria to combat and replace the red algae. This process takes time. After 5-7 days result will become visible. In some cases a second treatment is needed. Store in a dark place out of reach of children and pets.