“Natural” Aquarium Medications

12.4.1. “Natural” Aquarium Medications

There are a whole host of aquarium medications that are labeled as “Natural”. Sorry, I just cannot sugarcoat this:

ALL the claims made for “natural medications” on social media are simply parroted marketing hype designed to make money.  I.e. they are all simply “snake oil” and will not improve the health of any fish nor will they cure any fish disease. In most cases, they are actually detrimental to the health of the fish. All these “natural medications” are extremely cheap to produce and have huge profit margins. So of course every store and profit-minded website pushes them.

Below is a long and wordy analysis of natural medications. Only read on if you are a real nerd like the author.

Placidochromis Sp Jalo Reef
Placidochromis Sp Jalo Reef

What are “Natural Medications”?

Medications based on “organic”, “natural” remedies include the following:

  • Melafix tea-tree oil
  • Pimafix West Indian bay tree oil 
  • Herbtana
  • Microbe Lift Artmiss
  • Imagitarium Parasite Remedy
  • Easy-Life VOOGLE
  • Kordon Ich Attack
  • Kordon Rid Fungus
  • Garlic
  • Indian almond leaves (IAL)
  • Aloe Vera 

These are widely sold as “natural” and therefore “safer” alternatives to standard “chemical” medications such as copper and antibiotics. They are ALL WORTHLESS.  Sorry, just can’t sugar coat this fact.

Maylandia hajomaylandi albino
Maylandia hajomaylandi albino

Anecdotal Evidence

I’m not a big believer in anecdotal evidence but one piece sticks out. Ben Ochart, an African Cichlid Keeper with a YouTube channel, (great channel and a really likable guy!) had a deadly outbreak of bacterial disease. He treated with tree leaf oils (Pimafix and Melafix) and sadly lost many fish. The outbreak only stopped spreading when he used a sulfa drug and went away only when he finally used an antibiotic.

The question to ask those proponents of “natural” treatments is: If your elderly mother had pneumonia and was having difficulty breathing, would you give her herbs, or would you take her to the hospital for the latest antibiotics?

Since fish can’t communicate with us fish ailments are almost always serious by the time we notice them. So a relative with with a serious disease like pneumonia is a very good analogy to use.

Rocio octofasciata - Electric Blue Jack Dempsey
Rocio octofasciata, Electric Blue Jack Dempsey

“Research Papers”

Some people point out “research papers” that “prove” various natural remedies are effective. For example, take Indian almond leaves. Indian almond leaves (“Catappa leaves”) are grown largely in Thailand and exported for the aquarium trade. Several researchers in Thailand have published papers supporting the use of Indian almond tree leaves in treating disease (“The in vitro Antibacterial Activity and Ornamental Fish Toxicity of the Water Extract of Indian Almond Leaves”, Chansue et al., 2008,  “Potential Application of Extracts from Indian Almond Leaves in Siamese Fighting Fish Culture”, Purivirojkul 2012) .

Indian Almond Leaves
Indian Almond Leaves

This “research” has become the basis for an interesting widespread myth, namely that “Tannins are Mother Natures anti bacterials to help prevent illness“. This myth is parroted over and over again in social media, especially in betta fish sites.

Some folks aren’t cynical enough to make a connection between where the papers originated, the profit motive, and the results. The research was done in Thailand, where the Indian almond tree grows! The research was probably funded by the Indian almond leaf growers! What do you think it is going to say? Don’t be afraid to be suspicious! And follow up on your suspicions: investigate.  Research. Take the time to think it through carefully: it’s your money and your fish’s health!

How to Do a “Directed” Study
How to Do a “Directed” Study

Any tropical tree leaf (including Indian almond, tea and oak leaves) has some tannic acid in it. The Thailand research uses an interesting parameter. It reports the concentration in mg/ml, or milligrams per milliliter (which is 1 part per one thousand). Most scientists report their concentrations in mg/l, or milligrams per liter (which is 1 part per million), 1,000 times smaller than mg/ml.

The Thailand “research” shows that VERY VERY high concentrations of almond leaf EXTRACT (2.0 mg/ml or 2,000 ppm in one study, 0.3 to 0.75 mg/ml or 300 to 750 ppm in another study, i.e. water so dark you couldn’t see half an inch into it!) will have some antibacterial properties. LOWER CONCENTRATIONS HAD NO EFFECT ON BACTERIA BY THESE TWO STUDIES!!!!

Note the studies used the dried EXTRACT from the leaves, not the leaves themselves. This is a huge difference and means the level of leaves needed to create similar conditions is huge. A 20-gallon aquarium would need to have about ten gallons of leaves put in it to be effective at even slightly killing a few bacteria. So much for this profit-driven “research”.

Protomelas taeniolatius Red Empress
Protomelas taeniolatius Red Empress

Also note that this research showed that 50% of the bettas exposed to 1,700 ppm of Almond leaf extract died in 96 hours. If the bettas died when exposed to high concentrations then it is reasonable to expect that lower concentrations will probably not be very good for them. Tannic acid is a blood coagulant, which is not good.

Tannins are not used as antiseptics in treating wounds on humans, dogs or cats. They are not used in any way in human, dog or cat medications. This is revealing. While there is no regulation of claims made for fish medications there is strong regulation of claims made for human, dog and cat medications. So it a fish medication is not used in human, dog or cat medicine, it probably doesn’t work.

Hypancistrus sp. L 201 pleco
Hypancistrus sp. L 201 pleco

Many claim that “blackwater” created by tannins in the leaves is good because bacteria are inhibited by tannins. “Blackwater” is a very misunderstood phenomenon. Many think that that tannins color the water and that the tannins come from the leaves of tropical trees and make the water brown. They also claim these tannins in blackwater kill bacteria and are thus important. The actual story is almost exactly opposite that.

Because there is little salt in blackwater, bacteria cannot live in blackwater. Bacteria break down organic compounds into carbon dioxide and water. Without bacteria, the breakdown of organic substances goes to humic acid, which is brown to black in color. The acid in the bacteria-free water of the blackwater rivers is humic acid, not tannic acid. And neither humic nor tannic acid inhibits the growth of bacteria (“Ionoregulation in Tropical Fishes from Ion-poor, Acidic Blackwaters”, Gonzalez, et. al. 2008).

For more on the topic of blackwater go to this link:

17.3. Blackwater Fish

Andinoacara stalsbergi
Andinoacara stalsbergi


A hobbyist should not add any type of leaves to any aquarium. The leaves are carbohydrates in a form which breaks down relatively rapidly in the aquarium. This breakdown produces large numbers of bacteria and dissolved organic compounds (DOCs) which enter the water column. These bacteria and DOCs are a known cause of fish disease. The fish devote their immune system to fighting off these bacteria and bacteria feeding on the DOCs and have less immune systems resources for fighting off disease pathogens.

Indian almond leaves and wood are both cellulose yet wood has little or no negative effect on an aquarium while Indian almond leaves can have a significant negative effect. Plants that are woody remove almost all the nitrogen and phosphorus from the wood before leaving it as dead tissue. The wood is also designed for strength by Mother Nature and is typically quite dense and impenetrable.

Indian almond leaves on the other hand are picked green and dried. They thus have significant nitrogen and phosphorus in them. Leaves are also designed by nature to be porous and flexible, This means the leaves break down much faster and release potentially harmful amounts of DOCs while wood does not.

OB Peacock
OB Peacock

Melafix and Pimafix

The various “Natural” oils (Melafix and Pimafix) are just cheap oils pressed from the leaves of various species of Melaleuca, a tree closely related to eucalyptus. A tiny amount of these oils has a strong smell. So the hobbyists thinks they are doing something good for the fish.

Now there are some “research papers” (I would use different terms) that claim this or that in tea oil is effective against bacteria. If one studies these papers they are of two types: one is from several “universities” in the world where homeopathic remedies are “studied”. Others are from reputable universities where the papers use very careful wording where they don’t actually deceive one but they also don’t actually tell the truth either. If you take the chemicals found in tea leaves and apply them at high enough concentrations to bacteria they will kill the bacteria (and, at that concentration, they will kill the gills of any fish!). But if you use the concentration found in the water of an aquarium they do nothing to bacteria.

Gnathonemus petersii Elephant-nosed fish
Gnathonemus petersii Elephant-nosed fish

There is no genuine research papers that say these oils are effective against any disease and at least one research paper that says they are NOT effective. These oils are not approved by the FDA for use in humans or dogs and cats for any disease. These oils are not used to treat wounds or any external conditions in humans, dogs or cats. A US study found no efficacy for Melafix when used on aquarium fish. “Laboratory Evaluation of Safety and Efficacy for Melafix (Melaleuca cajuputi Extract)”, Shivappa et. al. 2015:


A study was performed at the North Carolina State University, College of Veterinary Medicine, to assess the safety and efficacy of Melafix, an aquarium product produced by Mars Fishcare Incorporated. Studies were carried out on the goldfish (Carassius auratus), a freshwater species, and the false percula clownfish (Amphiprion ocellaris), a marine fish. Animals were monitored closely and evaluated microscopically after exposure to Melafix according to the label directions for a period of 28 days. Water-quality parameters were monitored on a daily basis. The use of Melafix on goldfish and clownfish appears to be safe as no adverse effects were noted during the experimental period. The results also showed that Melafix has no effect on the water-quality parameters tested. In vitro efficacy studies were conducted by determining the minimum inhibitory concentration and minimum bactericidal concentration of Melafix on various pathogens. The study revealed that Melafix had no significant bactericidal or inhibitory effect on any of the pathogens tested.”

‘nough said.

Apistogramma rositae
Apistogramma rositae

Aloe Vera

Aloe vera is used in “stress coat” products supposedly to aid in fish diseases and after a water change to sooth the fish. Aloe vera is a polysaccharide, a polymerized sugar. It coats the gills of the fish and interferes with oxygen exchange. It also rapidly depolymerizes, forming sugar in the aquarium water column. This sugar will give a bacterial outbreak in the water column. This bacterial outbreak will kill fish.

The African Journal of Biomedical Research done study in 2005 which tested aloe vera in an aquarium with fish. The study saw an 80% mortality rate with fish exposed to 50 ppm for 72 hours. “Consumption of Aqueous Extract of Raw Aloe Vera Leaves: Histopathological and Biochemical Studies in Tilapia”, Taiwo et. al. 2005:

Forty-five juvenile tilapia exposed to water containing 50, 100 and 150 ppm of aqueous extract of Aloe Vera leaves for 96 hours and 28 days, respectively were used for this study. Fifteen tilapia exposed to clean water (0 ppm A. vera) served as controls. Clinical signs, mortality, gross and histologic organ pathology in the tilapia were monitored. Fish cultured in water containing A. vera exhibited erratic swimming patterns, rapid opercular movements, skin depigmentation and died within 24-96 hours.

Note that aloe vera has been the topic of many “research papers” (I would use a different term) by small third-world universities and some “homeopathic” research facilities which have uniformly resulted in glowing testimonials as to the effectiveness of aloe vera. Do not believe a word of it.

Pterophyllum scalar - Super Black Angelfish
Pterophyllum scalar – Super Black Angelfish


There are a whole host of “research papers” promoting “probiotics”, where adding a bacterial “soup” either to the food or the water has supposedly positively influenced the growth of fish. All the papers I’ve looked at are simply garbage. For instance, they almost all add the bacteria inoculate in the form of bacteria AND the nutrient solution the bacteria was grown in. Then in their controls, they do not add a nutrient solution. Thus all the conclusions of the test can be attributed to the nutrient solution rather than the bacteria.

The author showed conclusively that the addition of phosphate was very important to the biology of the aquarium during his tests on cycling with bacteria in a bottle products. All the probiotic nutrient solutions have considerable amounts of phosphate added. 

Reviews on the Web

With natural remedies (as with all products that can be purchased over the internet) the reviews on Google are only very glowing testimonials. This is simply because of the good old profit motive. The Google articles have underlined blue lettering on the natural products entry. When you click on blue lettering you are typically taken to an Amazon website. Buy the natural remedies on Amazon and both the website and Google get a commission. So what do you think the reviews are going to say?

Microglanis iheringi South American Bumblebee Catfish
Microglanis iheringi South American Bumblebee Catfish

Anecdotal “Evidence”

When this article is posted on social media about one or another of the “natural remedies” the predictable response is “But I used it and my fish got better!” or “Tannins from Indian Almond Leaves helped my one betta with stress and my other betta with fin rot so I know they work“.

Here’s the problem with this line of thinking: if one does absolutely nothing the majority of the time sick fish get better.  Fish have an immune system. These immune systems typically fight off 50% to 90% of the diseases they get without any treatment. So 50% to 90% of the time natural remedies “work” so often.

It is just very difficult for people not to believe that if one thing happens after another thing, then the first thing must have caused the other thing.  Everyone falls into this trap. It’s incredibly pervasive. You’ll see and hear it in newspapers, books, magazines, speeches, all forms of social media, friends talking. Everywhere. This hobby is no exception and you just have to guard against it.

The logic behind “This natural remedy worked”
The logic behind “This natural remedy worked”
Chaetostoma joropo L 445
Chaetostoma joropo L 445

Other hobbyists have another near-universal psychological phenomenon of “belief perseverance effect”.  It says that no matter how strong the science is refuting claims a hobbyist will continue to believe in the product. An actual response to reading the above data on Indian Almond leaves is this:

Almond leaves have been used for decades by hobbyists and breeders. They are known to have antimicrobial effects and I have seen them recommended by countless Betta experts. I use them with my bettas and shrimp and have had nothing but success with them. I highly recommend them.

More often than not, you will find that the more solid evidence you make available to refute such claims, the harder people will dig their heels in. That’s just human nature.

Cyathopharynx furcifer Blue Featherfin
Cyathopharynx furcifer Blue Featherfin

If you are of the mindset that “natural medications” work I have a good deal for you.  I checked Google Scholar and found two studies verifying the efficacy of a probiotic tonic effective against bacteria, fungus, ich, epistylis, bloat and popeye, The active ingredient is a patented derivative of an organosulfur compound from a rare member of the Alliaceae family kept secret for centuries by Tibetan monks. I have a supply that is the last that the monks will make for twenty years, It is only $99.88 per box.

Startpage Aquariumscience

Source: Aquariumscience.org – David Bogert

Leave a Reply

Your email address will not be published. Required fields are marked *


Neuws, Updates en Promotions

Would you like to be kept informed of News, Updates and Promotions on the AquaInfo website? Subscribe below!