Aquasonic Formalin Malachite Solution 250ml

Aquasonic Formalin / Malachite 250ml is a copper-free, fish-only treatment designed to combat whitespot (Ich), fungus, and a range of external parasites affecting the skin and gills of freshwater fish.

This dual-action formula also targets cloudy or slimy skin diseases, making it ideal for freshwater aquariums needing reliable parasite control.

Features & Benefits
Dual-Ingredient Formula
Combines Formalin and Malachite Green for a broad-spectrum treatment effective against common freshwater fish infections.

Effective Against Multiple Conditions
Treats whitespot, skin/gill ectoparasites, fungal growths, slimy skin, and cloudy patches.

Copper-Free & Fast-Acting
Safe for use in copper-sensitive systems (though not suitable for invertebrates), and delivers quick relief when applied correctly.

Trusted Australian Brand
Manufactured by Aquasonic, a respected name in aquarium health products.

When to Use
Fish show symptoms of whitespot (Ich)

External parasites present on skin or gills

Fungal infections or slimy skin disease

Suitable for fish-only freshwater aquariums

How to Use (Instructions)
Step 1 – Preparation
Remove all invertebrates before treatment. Turn off UV filters and take out activated carbon.

Step 2 – Dosage
Dose 5mL per 20 litres of aquarium water once daily for 4 days.

Step 3 – Temperature Boost
Raise water temperature by 2–3°C (within safe range for fish species) to increase treatment effectiveness, particularly for whitespot.

Step 4 – Aftercare
After Day 4, perform a partial water change and resume normal filtration.

Do not use in tanks with shrimp, snails, or other invertebrates.

Product Details
Size: 250ml

Treats: Up to 1,000 litres (over 4 days)

Target Conditions: Whitespot, skin parasites, fungus, slimy skin

Safe For: Freshwater, fish-only tanks

Not Safe For: Shrimp, snails, and invertebrates

Brand: Aquasonic (Australia)

Frequently Asked Questions (FAQ)
Can I use this in a community tank?
Only if the tank is fish-only. Do not use if invertebrates are present.

Will this harm my filter bacteria?
No, but it's advised to remove carbon filtration during treatment to maintain effectiveness.

Can I repeat the treatment?
Yes, if symptoms persist, you may repeat the treatment after a short rest period and a partial water change.