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How To Use Melafix For Betta Fish!

With the popularity of keeping betta fish skyrocketing right now as well as people choosing to spend larger and larger amounts of money on betta fish with rare colors and patterns, it is not surprising that we see so many people asking about treating bacterial infections in their betta fish.

With their longer tails and fins, some bacterial infections such as tail rot can be more common than average but things like eye cloud and mouth fungus can still be common with bettas.

With Melafix being a very common treatment for various bacterial infections in fish, we have seen a spike in the number of people asking about using Melafix for betta fish to treat bacterial infections at home as quickly as possible.

Although Melafix is an excellent product that can work well with betta fish, they are more sensitive than other fish so you should usually look at using Bettafix due to it having a smaller amount of natural active oil in it preventing issues with betta fish while still treating bacterial infections.

Even though Bettafix is a better option than Melafix for betta fish, a large number of our readers will probably already have some Melafix in their home due to keeping multiple types of fish in various aquariums.

This is why we are going to be going over how you are able to reduce the potential problems of using regular Melafix for your betta fish to get the best results possible.

Should You Use Melafix For Betta Fish!

With betta fish being at a higher risk of suffering from some bacterial infections that other fish, Melafix can present a great way to quickly treat the bacterial infection with ease.

The high amount of Cajeput Tree oil in Melafix usually means that you should heavily dilute it for use with betta fish and the usual recommendation is to dilute it twice as much as you would for other fish species.

This is due to Cajeput Tree oil being able to burn the gills and internal organs of your betta fish if not diluted at all.

If you follow the regular instructions on the Melafix bottle then this does drastically reduce the chances of your betta fish having any negative issues with the Cajeput Tree oil while it still treats the bacterial infections your betta is suffering from.

If you dilute the Melafix more than it is advised on the label, you will still be able to treat most bacterial infections while removing the potential health risks to your bettas gills from the Cajeput Tree oil.

There are countless reports from experienced betta fish owners online who have successfully used Melafix for any bacterial infections that their pet betta fish has suffered from without their fish having any problems.

Although there are also a number of reports of negative experiences from other betta fish owners after using Melafix for their fish, we would suspect that the issues inexperienced betta fish owners have are due to not diluting the Melafix enough for use with a betta fish.

Melafix Or Bettafix For Betta Fish?

Both Melafix and Bettafix are made by API with Melafix being the general bacterial infection treatment for fish and Bettafix being the specialized bacterial infection treatment for betta fish.

We would highly recommend that you use API Bettafix Betta Medication - 1.7 oz (93B) instead of Melafix for your pet betta fish if possible due to it having a lower amount of Cajeput Tree oil in it to reduce the potential risks to your betta while beating treat using Bettafix.

Although you are able to sufficiently dilute Melafix enough to use it safely with betta fish if needed, we would recommend against it if possible.

Bettafix has been optimised for use with betta fish so there’s no reason to take the additional risk of trying to dilute Melafix when there is a similarly priced product with an excellent reputation for treating betta fish with bacterial infections already on the market.

There are some Melafix alternatives on the market too but we usually recommend you stick to the official API products if possible.

The cheaper alternatives have a spotty track record when used with regular, non-sensitive fish so we would highly recommend you avoid even considering them for use with your betta.

How To Use Melafix For Betta Fish!

Although the official recommended dose of Melafix is 5ml per 38 litres of water in the aquarium, we usually recommend that you half this and go for 2.5ml per 38 litres when looking to treat a betta fish.

This will usually be around half of a cap per 38 litres if you use the standard Melafix cap for measuring your doses.

Even then though, we have seen a few reports that halving the dose of Melafix can cause problems with betta fish so you have to keep this in mind.

There are a number of variables for anything like this though and it may just be down to the bacterial infection taking hold and the lower dose of Melafix not being enough to treat it correctly.

This is why we recommend that our readers just go with Bettafix from the start as you don’t have to worry about trying to dilute it to get the right dose for your betta fish.

You simply follow the instructions on the label and you are good to go to treat your betta with a range of common bacterial infections.

Are There Side Effects Of Using Melafix On Betta Fish?

There are potential side effects of using Melafix on your betta fish if you do not dilute it correctly.

The Cajeput Tree oil in Melafix is the active ingredient to deal with the bacterial infection and it can coat the gills of your betta fish as well as some internal organs and cause a burning sensation. If possible, just use Bettafix, the variant of Melafix designed for use with betta fish to avoid this issue.

In some situations, if the bacterial infection on your betta has managed to get bad enough, you may have to use Melafix instead of Bettafix anyway and risk the potential side effects.

Due to Bettafix basically being a water down version of Melafix, you may need the full strength Cajeput Tree oil of Melafix to treat some bad infections.

If you are thinking of using Melafix to treat an algae eater or other fish in your bettas tank then it is usually a good idea to move the algae eater to a quarantine tank for treatment.

We have seen some people move the betta to a separate tank due to bettas usually doing better in a smaller tank than their suitable algae eaters but the amount of Cajeput Tree oil in the tank when returning your betta to it can still be strong enough to cause problems.


That brings our article going over using Melafix for betta fish to an end. We hope that we have been able to point out the more common problems that beginners make time and time again when trying to treat bacterial infections in their bettas. Ideally though, as we have said multiple times above to try and stress the point, you should really be using Bettafix to deal with bacterial infections in your bettafish.