Algae Control

I think this means absolutely disappointing help combat algae.
Like every year, I cleaned my pond of algae of last year, the plastic was then clean again black. The gravel in a 2 buckets 10l. The dosage of Algofin was this year, allow to react 0,5 l per bucket, fill with water a week and back into the pond.
Approximately a week later already the first algae veil came back coverage.
The one point there for the first delayed growth of filamentous algae (perhaps were particularly robust in my pond).
After several attempts by various means now my recommendation (came from one of my colleagues with a large garden pond)
and is not a joke:
untreated cow's milk in my pond, about 200-250 liters sufficed 0.2 liters.
The white haze is after a few days more and more transparent until it disappears entirely.
Although the existing algae will not disappear without leaving any residue, but also no longer continue to grow and the water runs clear down to the bottom. In addition, the cow's milk liter costs the farmer (in Bavaria) is just 50 cents.