Easy Alg Exit 250ml Algae are produced when an aquarium is not well balanced. Causes of an unbalanced aquarium are the excessive feeding of fish, too many fish in an aquarium, excessive lighting or excessive fertilization. You also take them home when you purchase fish or plants! Alg Exit is a safe & effective product for combating almost all types of algae in a freshwater aquarium. Algae, such as beard algae, brush algae & filamentous algae, are effectively wiped out. Alg Exit is easy & economical to use & harmless to fish, shrimps, molluscs & plants. The algae growth is first brought to a standstill & then it disappears. Any algae spores that are still present in the water are removed.