NT Labs Koi Care – Malachite Green

Ref: N/A



NT Labs Koi Care Malachite Green is an effective treatment for external parasite and fungus infections. Use this when fish have white growths on the body, head or fins, which may contain some green or brown discolouration. Malachite can be used in conjunction with Formaldehyde to treat fungal infections more effectively.

Available Sizes:

250ml – treats 20,000 litres (4400 gallons)

500ml – treats 40,000 litres (8800 gallons)

1 litre – treats 80,000 litres (17,600 gallons)

2.5 litre – treats 160,000 litres (35,200 gallons)

How to Use:

  • Test your water quality
  • Mix the appropriate dosage in a clean bucket of pond water, pour evenly over the surface of the pond and leave for 7 days. Switch off UV filtration until treatment has been completed. Aerate the pond well during treatment.
  • If you feel a repeat dose is necessary, check your diagnosis carefully using the NT Labs Diagnosis Tool; a different medication may be more suitable. Allow 7 days and perform a partial water change before re-treating or treating with a different medication.
  • Always treat when you have time to observe fish and take appropriate action in the unlikely event of a bad reaction.
  • If required, mix with Formaldehyde prior to adding to the pond, following the instructions above.



  • Always read the label.
  • Do not use with orfe, rudd, tench or sturgeon/sterlet.
  • Do not use if the water temperature is above 30°C.
  • Do not use in hot, humid, thundery conditions.
  • Do not mix medications other than combining with Koi Care Formaldehyde.
No additional delivery information...
No additional returns information...