£19.95 inc. VAT

Treats: White spot, Trichodina, Costia and Chilodonella.. 500ml – Treats 18000 litres / 4000 gallons

KOI Description

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SKU: 026357 Category: Tag:


Treats: White spot, Trichodina, Costia and Chilodonella.

250ml – Treats 9000 litres / 2000 gallons
500ml – Treats 18000 litres / 4000 gallons
1 Litre – Treats 36000 litres / 8000 gallons
2.5 Litre – Treats 90000 litres / 20000 gallons

When to use?
When fish show symptoms of a parasitic or fungal infection, including white spots along the fins and body, flicking and rubbing, gasping at the surface, an opaque film over the body or fluffy, white growths.

How to use?

Test your water quality using NT Labs Test Kits.
Mix the appropriate dosage in a clean bucket of pond water, pour evenly over the surface of the pond and leave for 7 days.
If you feel a repeat dose is necessary, check your diagnosis carefully using the 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.

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.

Q: Can I use FMG in a mixed-species pond? A: No. As this product is in our Koi Care range, it should be used in koi-only ponds. If you have a variety of species in the pond, our Pond range product, Eradick – Anti-Parasite & Fungus, is a more appropriate option; take a look. However, avoid using either treatment in hot, humid or thundery weather.
Q: Can I use FMG with salt in the water? A: Yes, provided this is at a concentration of 0.3% (or 3g/L) or lower. To accurately measure the salt concentration of your pond, use a hydrometer or ask your local fish shop to test a sample for you.
Q: How often can I repeat the treatment? A: You should wait 7 days after adding the dose before re-treating or using a different medication. Ensure you perform a partial water change after the 7 days have elapsed, regardless of whether another round of treatment is required.
Q: Can I leave my UV on during treatment? A: No, you should turn off any UV filters for 7 days from when you add the dose.
Q: Will FMG affect my water quality test results? A: No, so long as the colour has faded from the water. This should happen within a few days of the product being added.


Active Ingredients: Malachite Green 500 mg/100 ml, Formaldehyde 15000 mg/100 ml
Available in the following variations:

250ml, 500ml, 1 Litre & 2.5 Litre