Aquarium Medications and Treatments Part 1 | How They Work & Use
Aquatic Treatments, Which Ones to Use and Not to Use. AAP Information Library.
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PAGE TWO; ANTIBIOTICS/ ANTIMICROBIALS
*Triple Sulfa, *Trimethoprim, *Tetracycline Hydrochloride
*Minocycline, *Quinine Sulfate,
*Oxytetracycline Hydrochloride, *Nitrofurazone
*Neomycin Sulfate, *Metronidazole
*Kanamycin Sulfate, *Erythromycin
*Isoniazid, *Penicillin & Ampicillin, *Naladixic Acid
PAGE THREE; PARASITE & CHEMICAL TREATMENTS;
Internal Parasite Medications; *Piperazine, *Praziquantel, and *Levamisol
*Methylene Blue, *Mebromine
*Acriflavin Hydrochloride, *Malachite Green, *Formalin,
* Copper Sulfate, *Potassium Permanganate, *Hydrogen Peroxide
PAGE FOUR; ORGANIC TREATMENTS;
*Pimenta Extract (Pimafix), *Melaluca Tea (Melafix), *Oregon Grape
* Naphthoquinones (Herbal Ich Attack) *Usnea Lichen (Usnic Acid), *Others (Such as Herbtana)
By Carl Strohmeyer-PAMR 35+ years experience
I also strongly urge reader to read the companion article:
This article (Aquarium Medications; How to Use), has information about different aquarium and pond treatments. A gram negative or gram positive application is given where they apply.
Most bacteria which infect fish are gram-negative, including Aeromonas salmonicida, Flavobacterium columnare (Columnaris) Vibrio, and Pseudomonas species.
More about Gram Positive Streptococcus:
When you have fish that are sick (bacterial, fungal, or parasites), you want to try and isolate the fish in a hospital aquarium whenever possible. Of course, this should not be done if the infection is systemic.
Regular water changes before each treatment allows for a more effective treatment, especially when treated in the main display aquarium.
Sponge Filters work great in hospital aquariums. Remember to remove any carbon, as carbon will remove many medications. Also note that silicone in the aquarium will absorb Malachite Green, Methylene Blue, and Copper Sulfate (because they are a dye). Most corals crushed or similar, and ceramic decorations will also absorb medications.
Please see more on quarantine/hospital tanks in the Aquarium Disease Prevention Article: Aquarium Disease Prevention; Hospital and Quarantine Aquariums
Correct calcium content (positively charged calcium ions) levels are important (newer research shows this more than ever), as calcium helps in healing and stress.
As well, the addition of antibiotics, such as Tetracycline, will lower calcium absorption.
Initial steps that MUST be followed for best results :
Important, Finish Treatment!
Make sure that when you do treat with antibiotics, you follow the recommended course including all recommended does and FULL treatment amounts (for all fish), especially when fish improve. This is a point that many aquarists do not follow.
I've had aquarists confront me stating “I thought you said this medication would work, the fish got better, but then they got sick again and now they're worse than before”.
Change Medications when Ineffective:
Since fish treatment is far from an exact science. It's important to try another antibiotic if after three treatments no results are seen.
As I noted earlier, the majority of aquatic diseases are gram negative which make treatments with antibiotics such as Kanamycin or other gram negative antibiotics a good choice. This though is no guarantee that the disease pathogen will respond.
Metronidazole is sometimes a better choice than Kanamycin or Minocycline for anaerobic (NOT aerobic) gram positive bacterial infections (especially internal) with the side benefit of mild effectiveness for internal and some external parasites.
The bottom line is to read the other pages of this article such as Aquarium Medications Two, antimicrobials, antibiotics (LINK) to UNDERSTAND the strengths and weaknesses of each antibiotic used.
For instance, after finding some success in treatment with subsequent backslide with a mild aerobic gram positive treatment such as Melafix, the next course may be a treatment with a stronger gram positive medication such as Tetracycline while Erythromycin might be a another alternative.
The previous example is just that, an example and a case of a less common gram positive infection.
In the case of a gram negative infection that responding poorly to a treatment such as Triple Sulfa, sometimes using a combination treatment such as the before mentioned combination of Nitrofurazone and Kanamycin (especially if treating for Columnaris).
Also as noted earlier, sometimes combinations will allow for better effectiveness than each medication by itself (I would call this the cocktail effect which is employed in human treatments as well).
This principle also applies to chemical treatments for suspected protozoan infestations:
One point that I often use for both me and clients when microscopic evaluation is not possible is how the fish responded to a medication often is a determining factor in what the disease actually is.
Finally, often diseases are mis-identified, such as Fungus.
Water Conditions when Medications Ineffective;
Often when multiple medications are used, often in strong mixed "cocktails", this can damage the aquarium (or pond) ecosystem/chemistry.
Checking ALL these parameters is a must, often before a treatment regimen, but especially if "nothing seems to work". Check the following parameters:
My experience has often shown:Ammonia and/or nitrite levels are spiking. OR
Client has an unstable pH due to the lack of adequate KH buffers. OR
Positive mineral ions are missing (GH partly tests for these, although Redox is also part of this equation)
The usual causes of these are lack of established bio filtration, poorly treated tap water, or incorrect use of RO water.
Please read these articles for some overview of these problems:
When NOT to use Medication:
Many readers of my articles both here at American Aquarium Information and Aquarium/Pond Answers might think I m very pro medication use based on how much information is about medications and their use.
Here are some very simple points as to when NOT to medicate your fish (this includes organic remedies, as these too have side effects, despite the popularity and aura of "natural" around these treatments):
Back up Bio-Filtration:
As noted earlier, water changes before each dose are important to the effectiveness of treatment. The other aspect which may be important is the use of backup bio filtration. This is especially important when using medications such as Erythromycin which is hard on aerobic gram positive bacteria and nitrifying bacteria.Having on hand separate sponge filter, bio media, even gravel in a healthy tank that can be added as needed to the tank under treatment, can go a long way in making a treatment effective.
A soaring ammonia level in an aquarium can cancel the benefits of any treatment. I recommend testing ammonia during a treatment, especially with Erythromycin and Tetracyclines.
Then add this bio media at the first sign of an ammonia increase.
If this is not possible or in addition the above suggestion, the use of SeaChem Stability or similar facultative bacterial aids should be added approximately 12 hours after each medication treatment dosing to aid in maintaining your bio filter
A SeaChem Resource: SeaChem Stability
Remove Carbon (& other chemical filter media):
Although most experienced keepers are aware of this, many “newbies” are not.
If you use filter cartridges, the answer is simple in most instances.
Also note that some other types of chemical filter media such as Boyd’s Chemi-Pure or Filstar's Bio-Chem Zorb can also remove medications and should be temporarily discontinued during use of aquarium medication treatments.
Carbon or other similar chemical filter media can be replaced after treatment is finished or added to the filter temporarily for 2 hours prior to each subsequent treatment, then removed again.
SeaChem Purigen is another good product to use during treatment intervals or after treatment, more to the point, I STRONGLY suggests its use for a couple hours just prior to EACH treatment and then after treatment is complete!!
The purpose of this is to remove any residual toxins that may have built up during each treatment dose which Purigen is uniquely able to perform. However, this is not required and is only an option to improve water conditions during treatment.
Mineral treatments (such as Regular Wonder Shells), buffers, or similar water chemistry additives can safely be used during aquarium medication treatments.
If bio filtration additives, such as SeaChem Stability are required due to ammonia or nitrite issues, these can be added about 50% of the time between each treatment dose.
Changing water immediately prior to each treatment or every 48 hours can improve effectiveness and lower the possible toxicity of treatment. For food soaks, once every 48 hours is also suggested.
As well some medications break down after 24-48 hours and can leave mildly to moderately toxic chemicals behind which a water change prior to the next treatment can help lower or remove completely. As noted in the previous section, placing carbon or similar products such as SeaChem Purigen in a filter for an hour or two prior to a treatment can help remove ineffective or exhausted medications.
Tetracycline and Malachite Green are two examples of treatment medications that can be both more effective and less toxic if water changes (and/or carbon filtration) are performed immediately prior to a new or follow up treatment.
Be aware that many chemical dyes such as Malachite Green can be at least partially removed by most water conditioners such as Prime, Start Right, Amquel+, etc.
However we want to be careful to not change TOO MUCH WATER, as this can dilute medications, in particular the use Medicated Wonder Shells or similar slow release medications.
Often a reason to change water is to prevent toxic build up of ammonia or nitrites in a treatment tank. However if your ammonia never exceeds .5 ppm your need for a water change for this reason is basically nil.
As an example; I have made medication recommendations to many over the years, in particular non contract (non regular) service customers where by I set up a treatment regimen that in the end failed. In investigating, I found that they were changing 50% to 100% per day with no testing of ammonia to see if necessary. The result is the medications were not at therapeutic levels the proper amount of time to be effective.
Why I do not use Diagnostic Charts:
Readers of my Aquarium Information sites might also note that I do not use diagnostic charts.
I will admit I've seen a few charts that have better flow than others, however even these do not take other variables into account. This often includes water conditions/parameters that can effect correct diagnosis of disease pathogen.
For example: A fish with a Red Sore.
Columnaris can also cause similar symptoms. It also is an opportunistic bacteria where improving electrolytes would also help (Calcium/Magnesium positive mineral ions).
This is an important point. When medications do not work, it is often not a problem with the medications which is often assumed, but with water parameters and the choice of medication that was used for the problem.
This point also extends to parasitic diseases such as “Ich”. Medications such as Malachite Green are not only more effective in water with pH above 7.2 and a GH over 150 ppm. It's less stressful to the fish and the necessary electrolytes such as Calcium further buffer and aid in osmoregulation which further helps the fish resist an infestation.
Much more information on diseases referenced:
To further summarize why diagnostic charts should be avoided is that they are simply people's opinions which are often vague.
How can we expect an aquatic diagnostic chart to be any more accurate when we have less tools and vastly less money for diagnosis at our disposal?
Effect of Water Parameters:
Make sure all your water parameters are where they should be. For example, if your ammonia levels are high and all the medication in the world will not help, make sure you have proper water circulation, dissolved oxygen, and low waste particulates. Otherwise your Redox Balance can be adversely affected (Redox Potential does not need to be worried about for the average aquarist). Adequate calcium levels (which can be partially measured by kH) are very important to proper osmotic function.
I would like to address the common anecdotal comments made by many people about the harmful side effects of medications. While almost every medication has a side effect which can harm or kill a fish, only over use or misuse can result in harm. Even in human treatments, what can cure can also harm.
A comment often stated is the use of antibiotics will kill your nitrifying bacteria.
The majority of aquarium infections (especially in marine aquaria) are gram negative. So the use of gram negative antibiotics such as Kanamycin (which is primarily gram negative) have a lower risk of a nitrifying bacteria die-off than when used properly/carefully in an established aquarium.
Another example is Malachite Green. This has been shown in studies to be carcinogenic when used in large quantities.
Here's another of piece medication misinformation or what I consider jumping to conclusions. In this area of two products by API; Melafix and Pimafix have recently fallen victim to aquarists and forums making assumptions based on poor scientific method.
Basically I have read aquarists in forums stating Pimafix should not be used due to Clove Oil being in this product, however this is the same as stating a human should never use Tylenol as over use (especially with alcohol) can lead to liver failure.
Melafix has been blamed for the death of Labyrinth/Pencil fish, which I am not doubting the sources (such as Fish Lore) are reputable, but since I and others have conducted tests with Melafix at double dose with Labyrinth fish with no ill effects, I think we have to look scientifically at what the trigger may be (I explore this problem further on page four of the Medications article as noted earlier).
Another common problem is many will use only part of a treatment regimen, leaving out key synergistic combinations such as Nitrofurazone & Kanamycin (as found exclusively in AAP Spectrogram).
Making False Assumptions when Medicating:
This is similar to the section above, however here I'm referring to aquarium and pond keepers use of medications vs. the previous section dealing with anecdotal advice.
A good example is the use of Erythromycin or Melafix for treating Columnaris which is gram negative and then assuming your use of Erythromycin cured this ailment when laboratory tests prove this impossible.
Changing water or otherwise improving water conditions can often allow a fish overcome an opportunistic infection (such as Aeromonas). This easily allows the aquarium keeper to assume that a treatment cured his/her fish.
My point is that this hobby is often driven by anecdotal assumptions that I would like readers to avoid by thinking more scientifically.
However by changing water before treatments (even before each additional treatment), keeping water parameters where they should be for the fish kept, and knowing what each treatment method can and cannot effect, as well as proven/known effective treatments for bacterial & parasitic pathogens can allow an aquarist to know when an infection treatment is the best possible to utilize.
Best Used By or Expiration Dates for Medications & Fish Foods:
Despite common belief, 95% of medications AND Fish Foods are still quite effective well past their expiration/best used by dates printed on packages (generally an antibiotic is at least 90% + effective 6-12 months after said date).
Many organic treatments such as Melafix can last for years past their expiration dates (I used some Melafix that was two years past its date with positive and measured results).
These “dates” are in part made by regulations (often under false assumptions) as well as companies which manufacture these products who know when you discard a medication, you will likely purchase a replacement.
If you doubt this, a quick search on the internet, including medical sites will prove this correct. Don't believe what you read on Yahoo Answers or similar anecdotal sites.
Here a couple references:
Gram Negative/ Gram Positive Bacteria
*Gram-negative bacteria are pathogenic, as they can cause disease in a host organism and have a thin cell wall. Gram negative bacterial infections are much more common in fish, especially marine. These bacteria that will NOT retain a crystal violet dye during the Gram stain process.
Here are some Gram Negative Bacteria:
Aerobic Chemolithotrophic Bacteria:
Anaerobic Chemotrophic Bacteria
- Cyanobacteria (Oxygenic Phototrophic)
Gram-positive bacteria do not always cause a disease in the host organism and have a very thick cell wall.
Here are some Gram Positive Bacteria:
-Mycobacterium (aquatic tuberculosis)
Of the above bacteria noted, Flavobacterium (Columnaris), Vibrio, Aeromonas, & Pseudomonas cause the vast majority of diseases in aquariums/ponds AND these are gram negative. It should also be noted that Aeromonas and Vibrio are generally anaerobic, so keeping a well circulated/oxygenated aquarium or pond is important for their prevention and treatment.
I have cited much of the information for this section from this source:
Contraindications (& Medication Mixing):
What are "Contraindication"?
With this in mind I have added a "Contradindications" section under many explanations of each medication treatment on page 2 and page 3 of this article.
Knowing some of these contraindications will help determine whether it is advisable or at all safe to mix certain medications or chemical treatments. As well, the mix of medication and volume depends on the disease you are trying to treat and the inhabitants of your tank.
Here are some examples of medications that can or cannot be mixed:
Food Delivery of Medications:
For many internal infections soaking medications in food or the use of prepared medicated food is the best coarse of action in freshwater, however marine fish do not usually require delivery of medication via food due to their constant drinking of water around them.
I soak these foods in a few tablespoons of water with the medication for about 15-30 minutes then add everything to the aquarium or pond. Prepared frozen foods (such as by Ocean Nutrition can be used too.
If your fish food falls apart with the soak (flakes and especially high fiber dehydrated crumbles have more issues here), this can be overcome by than pouring "feeding rations" into custom foil pouches and frozen for easy feeding later. I did this for many of my professional aquarium maintenance clients who did not have time or were not willing to prepare medicated fish foods.Even for external infections such as sores, injuries, etc, this may be the more simple coarse of action for very large aquariums or ponds over 500 gallons as "in tank" or fish removal is cost prohibitive or nearly impossible.
These are the medications I find work well for internal infections/infestations when soaked in a fish food "slurry";
For internal gut infections that often result in bloating or swim bladder infections, I have found the combination of Metronidazole with Neomycin to be most effective since one is effective against aerobic while the other is effective against anaerobic bacterium (this combination also addresses mild intestinal parasitic infections).
For suspected intestinal worms, the combination of Metronidazole & Praziquantel can be useful. For more serious intestinal parasite infections Piperazine/Pipzine is a better choice and safer than Levamisol.
The use of Medicated Wonder Shells may be helpful to address the above issues in tank as well as supply important mineral Cations often necessary during any treatment and often missing if RO water is used.
Generally a dose intended for 2-5 gallons of water treatment will work for a 15-30 minute fish food soak
For a pond or very large aquarium, I would suggest a dose intended for 10 gallons, then pour the food, water, & medication mix all directly into the pond.
A 20% water change every other day (48 hours) is also suggested (reference water change section above)
How to Make a Percent-% Solution:
Sometimes it is necessary to mix your own chemical solutions such as Methylene Blue, Malachite Green, Potassium Permanganate, etc.
Simply put- to make a 1% Malachite Green aqueous solution, use a 100 ml bottle. Then add 1 gram of Malachite Green to your bottle and bring the volume up to 100 ml.
See this equation:
I have stated this in other articles as well. I personally have resisted adding disease charts as these just show up all over the internet, many are very “cookie cutter” in their descriptions. I feel first understanding prevention methods followed then by a knowledge of antibiotics, chemical treatments, and organic treatments will go much further in treatment and disease prevention than any disease chart that has a one size fits all approach.
Make sure to check out more information on: Aquarium Disease Prevention/p>
For some pictures of fish anatomy that may be useful in disease recognition, please visit this article: “Aquarium Answers; Fish Anatomy”
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