Fish Medications

API Melafix

FreshwaterAll-naturalPlant safe

API Melafix is the bottle to reach for when a fish shows torn fins, a white patch around the mouth or a cloudy eye. Made from an extract of melaleuca, the tea tree, it works on the external bacterial infections behind fin and tail rot, open wounds, eye cloud, popeye, body slime and mouth fungus, and it helps damaged fins and skin grow back. It also doubles as a precaution for new fish. Dose 5 ml per 38 litres once a day for seven days, then change 25% of the water. Bottles of 118 ml, 237 ml and 473 ml are available in South Africa through Jungle Aquatics.

Size: 118 ml

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Live pricing and stock on jungleaquatics.com — purchase through Jungle Aquatics, with delivery across South Africa.

Dosage calculator

Enter your aquarium volume and the calculator works out how much API Melafix to use for each rate on the pack.

Aquarium volume

Measured in

Use the water the tank actually holds, less substrate and decor.

Treating infection or injury5 ml per 38 litres
Enter a volumeOnce a day for 7 days, then a 25% water change
Settling new fish5 ml per 38 litres
Enter a volumeOnce a day for 3 days

Remove activated carbon and other chemical media from the filter for the whole course.

A guide only — always follow the dosing instructions printed on the pack, and measure with the bottle's cap or a syringe rather than by eye.

Technical details

Product type	All-natural antibacterial fish remedy
Sizes	118 ml, 237 ml, 473 ml
Dose	5 ml per 38 litres, once a day
Treats	118 ml treats 870 litres · 237 ml treats 1 779 litres · 473 ml treats 3 558 litres
How often	Daily for 7 days (3 days when adding new fish)
Water change needed	25% after the 7-day course
Suitable for	Freshwater aquariums, including planted, shrimp and snail tanks (API makes a separate Marine Melafix for marine systems)
Safe with	Live plants, shrimp, snails and the biological filter; does not alter pH or water colour
Key ingredient	Melaleuca (tea tree) extract
Made by	Mars Fishcare, USA

Dose by the water actually in the tank, not the tank's nominal size, and keep activated carbon out of the filter for the full course.

How much Melafix do I dose, and for how long?

Add 5 ml for every 38 litres of aquarium water once a day. For an infection or a wound, keep that up for seven days, then change 25% of the water; if the fish is still healing, repeat the course. When you are simply settling in new fish, three daily doses are enough. Take activated carbon out of the filter before you start, because it strips the remedy from the water. For sizing, a full course on a 100-litre tank uses about 92 ml: the 118 ml bottle covers one course on tanks up to roughly 125 litres, the 237 ml up to about 255 litres and the 473 ml up to about 510 litres.

Treats the bacterial infections you can see

Frayed or rotting fins, a raw patch from a scrape or a fight, a milky film over one eye, a swollen eye, a slimy coat on the body or cottony white growth at the mouth are the classic signs of an external bacterial infection. Melafix acts on these directly and, as the infection clears, supports the regrowth of the fin rays and skin that were lost.

A seven-day course with one water change

Add 5 ml for every 38 litres of water once a day for seven days, then change 25% of the water. If the fish is still healing, run a second course. For new arrivals, three daily doses ease the move from shop to home and cover an infection that was picked up before purchase but has not shown itself yet.

Leaves the filter, the pH and the plants alone

Melafix does not knock back the nitrifying bacteria in your filter, does not move the pH and does not tint the water. It is safe with live plants, shrimp and snails, so it goes straight into a community tank without moving anyone out. Do take activated carbon out of the filter for the week, because carbon soaks up the remedy before it can work.

Pairs with Pimafix for stubborn or mixed infections

When a fish has a bacterial wound and a fungal growth at the same time, or a single infection is slow to respond, Melafix and Pimafix are meant to be dosed together at their full, normal rates. Melafix can also be used alongside any other API remedy; just keep to two products at a time unless you are sure of each diagnosis, so you can tell what is working.

Frequently asked questions

Which aquariums can I use API Melafix in?

Freshwater aquariums of every kind, including planted tanks and tanks with shrimp and snails. It will treat the same symptoms in saltwater, but API makes a dedicated Marine Melafix for marine systems and that is the one to use there.

Can I dose Melafix and Pimafix at the same time?

Yes, and API recommends the pair for stubborn infections or a fish with bacterial and fungal symptoms together. Dose each at its normal rate with no reduction, and keep to two remedies at once unless you are certain of every diagnosis.

Do I need to remove carbon or switch anything off while dosing Melafix?

Yes. Take activated carbon and other chemical media out of the filter for the seven days, and switch off any protein skimmer, because Melafix foams and a skimmer will strip it from the water. Once the course is over, fresh carbon or Bio-Chem Zorb clears the remaining remedy.

How do I know whether my fish has a bacterial infection and not something else?

Bacterial problems usually show as frayed or rotting fins, open sores, a cloudy or bulging eye, a slimy body coat or white growth around the mouth; pinpoint white spots point to a parasite and fluffy tufts to fungus. Match what you see to the symptom list on each API remedy, and if it is still unclear after a full course, a vet or the Jungle Aquatics team can help you narrow it down.

My water has gone foamy since I started Melafix. Is that normal?

A layer of foam is normal with Melafix at the correct dose and it is not harmful. How long it lasts depends on the dissolved organics in the water; if it is still foaming more than a week after you stop, do a couple of extra water changes and run activated carbon.

Is API Melafix available in South Africa?

Yes. All three sizes are sold by Jungle Aquatics in Fourways, Johannesburg, with delivery across South Africa; current pricing and stock levels are on jungleaquatics.com.

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South Africa's leading pet and aquarium store since 2007 — with the API range on the floor in Fourways, advice from people who test water every day, and easy ordering from anywhere in the country.

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