Aquasonic Formalin / Malachite 250ml – Effective Parasite & Fungal Treatment

Product Overview

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.