Hydrogen peroxide is especially effective against green algae and blue-green algae (cyanobacteria). It is heavier than water and sinks to the ground, which is useful if you're dealing with algae near the ground and somewhat of a hindrance if the algae are higher up in the tank.
How long does it take for hydrogen peroxide to kill algae?
Concentrations of around 60ml of 3% H2O2 (30ml of 6%, 15ml of 9%) in a 250 Litres (66US G.) tank directly applied (usually via a syringe) slowly over 5 minutes onto a clump of algae will kill it and then rapidly be diluted and converted into harmless oxygen and water.
How do you use hydrogen peroxide for algae?
Depending on the algae species, we recommend different dosages:
- In the case of blue-green algae: 8 to a maximum of 15 ml of the 3% solution of hydrogen peroxide per 50 liters of water.
- In the case of green algae: 25 to a maximum of 35 ml of the 3% solution of hydrogen peroxide per 50 liters of water.
