Tetra Broad Spectrum Algae Control - 1.69 oz is designed to support clean, balanced aquarium water. Keep your aquarium clean and algae-free with Tetra AlgaeControl Broad Spectrum Algae Control Water Treatment. Algae is a common aquarium problem, but if left untreated it can cover the glass, filter, decor and substrate. Tetra AlgaeControl Broad Spectrum Algae Control Water Treatment contains poly ethylene to control a broad spectrum of algae including green, string and hair algae and blanket weed. Shop Tetra aquarium water conditioners at Uncle Bill's Pet Centers for trusted pet supplies and knowledgeable service in Indiana.