Algae Control (3.38 oz) Tetra AlgaeControl liquid not only combats aquarium algae, it also works to keep it from returning. AlgaeControl liquid is highly effective against green water (algal blooms), blue-green algae, diatoms or brown algae, hair algae or blanketweed that grow on the glass and décor. Unlike some other products on the market, Tetra AlgaeControl liquid can be safely used in planted aquariums. Tetras precision dropper tops help consumers administer the proper dose to their aquarium..