Hi – I’m a member of the customer care/tech services team at Mars Fishcare, and I’ve been asked to address the Melafix/bettas/labyrinth fish “controversy.” Our medications are all thoroughly tested in their development phase, both for efficacy and for fish safety – we definitely do our homework. Not unsurprisingly, bettas and a wide range of other labyrinth fish were (and are) among the fish regularly exposed to Melafix (as well as Bettafix and Pimafix), and we’ve seen absolutely no indications that any fish are adversely affected by it, bettas or otherwise. On a side note, the same is true of pencilfish – when the first rumors started there, a number of trials were run specifically on them (on all species available in the trade at that time), again with no signs of trouble.
I agree that many of the problems reported with Melafix are the result of improper dosage. The phrase “if I had a nickel for every time…” springs to mind: All too often I speak to well-meaning but misguided hobbyists who think that “a little bit” or “just a few drops” of the medication MUST have been safe, even though they have no idea of the volume of their betta’s home. Anything can harm fish if overdosed; likewise, anything can be ineffective if under-dosed.
I often see references to Bettafix being somehow safer than Melafix due to its lower concentration of melaleuca extract. In reality, however, the end concentration in water comes out the same – yes, Bettafix is weaker, but you use more of it. The reason for this is that many betta keepers use small bowls, and dosing with Melafix is difficult under such circumstances. It’s difficult for the typical hobbyist to accurately measure the .125 ml of Melafix needed for a quart of water. Think of how small a volume of liquid that is: 1 ml is the amount of liquid that fits in a cube 1 cm on a side, and .125 ml would be one eighth that amount. I know I couldn’t accurately measure that amount if my life depended upon it, unless I had graduated pipette. The addition of, say, an eighth of a teaspoon to a one quart betta bowl would be a potentially harmful 5X dose! That would be bad enough for a fish in perfect health, let alone one already comprised by illness.
As has been pointed out in most of the forum threads dealing with this subject, Melafix is a medication – hobbyists are using it to treat an existing health problem, not just as a general additive to the water of a perfectly healthy fish. And keep in mind Melafix and Bettafix are for topical bacterial infections and wounds – nothing else. Velvet, which IME is fairly common in bettas, will not be affected, and can be hard to diagnose.
The point about Melafix being dangerous in situations where water quality has been compromised is a bit trickier. We don’t subject fish here in the lab to that kind of “stress test:” We know that poor water quality will harm fish, and we won’t subject fish to conditions we know can have a fatal outcome. And such tests would have to be exhaustive – is ammonia the problem? Or nitrite? Or dissolved organics/proteins? Phosphates? What levels of each? What combinations? Testing medications’ effects under conditions already unfavorable to fish health would be a full-time job, not to mention irresponsible. That said, while I’m not sure I’m convinced Melafix could cause harm if water quality is sub-optimal…don’t subject fish to sub-optimal water quality! If you have any doubts, address any and all water quality issues before using ANY medication – not just Melafix. That’s simply good fishkeeping practice.
To address another point, I often see variations on the phrase “it’s not even an antibiotic.” That’s true – it’s an antibacterial (and most definitely NOT an antiseptic, as some claim). Antibiotics are also antibacterials. The term antibiotic doesn’t denote any particular degree of efficacy; it only refers to the chemical’s original source. Antibiotics are those antibacterials which are produced by other microorganisms (fungi or other bacteria) to combat bacterial growth, but the term also includes synthetic versions of such antibacterials, as well as chemically modified versions of these naturally-produced substances. If the antibacterial is produced by a plant or some other form of life, or if it is a unique synthetic not based upon or derived from another antibiotic…it’s not an antibiotic. “Antibiotic” doesn’t mean an antibacterial substance is necessarily more hardcore, or more effective – it simply refers to the origin of the chemical.
There are quite a few extremely effective non-antibiotic antibacterials. Melafix is one. Interestingly, it seems more effective in vivo (that is to say in or on the fish) than on free-living bacteria. We saw cases where Melafix would not adversely affect bacterial colonies in a dish, but would clear up a topical infection of the same bacteria on living fish. This suggests (I have to be careful here – it certainly doesn’t PROVE) that it may benefit the immune system of fish, or it could simply mean that Melafix interferes directly in whatever chemical pathways bacteria use to invade living tissue. I bring this up mostly due to the suggestion that Melafix is topical while antibiotics are not. Most aquarium remedies are strictly topical, including antibiotics. As a rule (there are exceptions, of course), if it dissolves in water, it won’t end up inside the fish’s body. We have seen a good degree of efficacy in treating Flavobacterium (columnaris) and do get good hobbyist feedback regarding the use of Melafix to treat “cottonmouth.”
Another point to keep in mind is that Melafix is a plant extract, meaning it is not one chemical – it is a mixture of substances produced by the Tea Tree. We’re not certain which one, or, more likely, which combination of them provides the therapeutic effect. Because Melafix is a “cocktail,” pathogens will be much less likely to develop resistance.
Interestingly, Pimafix seems to have some efficacy on systemic infections, provided treatment is begun early enough. We haven’t done much testing in that regard, but there is sufficient evidence for us to desire future testing in this application.
I hope this has cleared the air a bit. If you have any questions, you can contact us further via our website, or our toll-free number (found on any of our packaging).
Thanks and best regards!