Tetra Pond Algofin  For Blanketweed control  For Blanket weed control HSE approved algaecide for blanketweed. Safe for fish, plants, and wildlife.   Use Biocides safely. Always read the label and product information before use.  Application  Add 50ml of AlgoFin for every 1000 litres (220 gallons) of pond water.  Shake the bottle well before use. Add a half dose every 4 to 6 weeks for long-term suppression .  Always read the instructions carefully before use.