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Kusuri 30% Formalin and Malachite Premix is a ready to use full strength formulation, popular as a pond-wide anti-parasite treatment. It is particularly good for White Spot, Skin Flukes, Chilodonella, Oodinium and most Protozoan Parasites.


Do not use below 12.5°C (54.5°F).


Please ensure that you read, understand and follow all Health and Safety guidelines on the bottle.


Please do not eat, drink or smoke whilst handling chemicals.


Wear disposable vinyl or latex gloves and appropriate eye protection.


250ml treats 11,350 litres (2,500 gallons) of pond water

500ml treats 22,700 litres (5,000 gallons) of pond water

1 litre treats 45,400 litres (10,000 gallons) of pond water



Use 10ml per 100 gallons (454 litres) of pond water. Treat up to 3 times, 7 days apart.

DO NOT OVERDOSE. Over-dosing can cause fish fatalities.


For our handy dosage calculator, click here!


For use above 12.5°C (54.5°F)


How To Use

  • Switch off UV steriliser until course of treatment is complete.
  • Tighten cap and mix well.
  • Use cup supplied to measure the correct dose.
  • Add water to a clean watering can, then add Formalin/Malachite Premix.
  • Gradually sprinkle across the surface area of the pond over a 1 hour period.
  • Do not use below 12.5°C.
  • Do not use Malachite and Formalin Premix in conjunction with salt.
  • Stop feeding during the course of treatment because Malachite and Formalin will reduce the bacteria in the filter, continuing to feed will cause an ammonia spike.
  • Once the course of treatment is complete monitor your water parameters regularly.

Kusuri FMC Pre-Mix

SKU: MD918
PriceFrom £23.00
  • Collection from our premises near Chepstow in South Wales by appointment or delivery to British mainland addresses.


    Delivery is £8.95 per order for most dry goods, with some more expensive delivery charges applicable for very heavy or long items.


    Please note delivery for dry goods is typically 2-5 working days and items may be sent in separate packages.

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