Prevents thread algae


Product to prevent and combat algae in all garden ponds
  • For clear, healthy pond water
  • Natural barley straw inhibits algae growth and causes any present algae to die off
  • Humic peat, oak bark and alder fruit reduce and regulate the pH
  • A slightly golden brown to brownish coloration of the water deprives the algae of essential light energy
  • Made from renewable raw materials

An effective and reliable agent to treat thread algae, which can be used as a preventative as well as to fight algae, is barley straw. Barley straw inhibits algae growth through its decomposition and causes any algae present to die off.
Dennerle Algae Stop also includes humic peat, oak bark and alder fruit. These reduce and regulate the pH as algae require high pH values. A slightly golden brown colour also filters algae-promoting UV light.

Duration of use:
To fight algae:1 kg pack - 5,000 l / 3 kg pack - 15,000 l
For prevention:1 kg pack - 10,000 l / 3 kg pack - 30,000 l


Art. no.Contentsfor
34651.000 g5.000 l
34663.000 g15.000 l
  • Application:

    Remove as much of the existing algae as possible by hand so that they will not pollute the water when they die off.
    Fill corresponding quantity into the mesh pond bag enclosed in the package. Maximum filling quantity in each mesh bag: 15 dosage scoops / 1.0 kg (product will swell heavily)!
    Do not sprinkle pellets directly into the pond! Close the mesh bag and place it in the pond in a position with good water flow.

    Ensure a good oxygen supply during the application, e.g. by additional ventilation (pond aerator) or a corresponding water movement (filter, watercourse, bubbling rock). A possible slight water turbidity at the beginning of the treatment is harmless and will disappear after a short period of time.

  • Dosage:

    To fight algae: 3 dosage scoops (200 g) of AlgenStop in 1,000 litres of pond water.
    To prevent algae: 1 ½ dosage scoops (100 g) of AlgaeStop in 1,000 litres of pond water.

  • Duration of effect:

    In the course of 1 to 3 weeks after the application most of the algae begin to die off or their growth is slowed down in the long term. Time and effectiveness depend, for example, on the type of algae, solar radiation, temperature, oxygen and nutrient content of the water. The duration of effect is 6-8 weeks - after this period AlgenStop should be renewed. Long-term use is possible.

  • Active substance:

    Natural barley straw - does not fall under the Biocides Regulation 528/2012.
    Disposal: Used AlgenStop and unused pellets: Compost heap / organic waste bin.
    Store away from sunlight, heat and frost. Store in a dry place.