Humblefish
HF
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Antibiotic treatment (updated 1-12-23)
What It Treats: Bacterial infections, which are oftentimes “secondary” to preexisting parasitic (and worm) infestations.
How To Treat: Follow the directions for whatever product you are using. Always use a broad-spectrum antibiotic i.e. one that treats both gram-positive and gram-negative bacteria. It is preferable to use pharmaceutical-grade medications when treating fish. (Sources for Pharma grade: Here, here and here.) Keep in mind that with pharmaceutical-grade medications a digital scale should be used to weigh the dosage: https://www.amazon.com/dp/B0012TDNAM/?tag=humblefish-20
The following are antibiotics I recommend (in order of preference):
When using antibiotics, it is very important to treat for 7 - 14 consecutive days. Sometimes a fish will look & act better after just a few days; however the infection can return if you end treatment prematurely. Or sometimes you may not notice any improvement right away, as antibiotics can be notoriously slow-acting with fish. It is also best to use Pharmaceutical-grade antibiotics instead of aquarium products if possible (this short video explains why). This sticky contains dosage info for many Pharma grade medications (including antibiotics): Medication Dosing Guide
The medications listed above are primarily meant to be dosed in water. Using antibiotics in a QT environment (or bath treatment) fits within the comfort level of most hobbyists. However, the absolute best way to apply antibiotics is via intramuscular injection (which is obviously difficult to do with small fish.) The first step is to sedate the fish using MS-222 (Tricaine Methanesulfonate). Next, inject an antibiotic (e.g. enrofloxacin), or a steroid such as dexamethasone to help reduce inflammation/swelling. The injection is made into the muscle on the side of the dorsal ridge (video here), angling the needle towards the head or tail to avoid hitting any major organs below. Typically you would use a tuberculin syringe with a 27 gauge needle to draw up the solution and a 30 gauge needle to inject. After the injection is complete, place the fish in a heavily oxygenated bucket with clean saltwater and glide the fish through the water until he is revived. Dosage for Intramuscular dexamethasone varies from 1-2 mg/kg, and for enrofloxacin it varies between 6.14 to 9.69 mg/kg. For most other antibiotics the dosage ranges from 4 to 10 mg/kg. (Mg=amount of medication, kg=weight of fish)
You can also food soak antibiotics; this is especially useful for treating internal infections. Neomycin will not get absorbed by a fish’s gastrointestinal tract, thus making it an excellent antibiotic to lace in food. I’ve also had success by food soaking kanamycin. Metronidazole is another good option and can also be used to treat internal flagellates. See Table 1 (here) for other antibiotics which can be soaked in food. It is also important to use a binder to reduce loss of medication to the water through diffusion (this also makes food soaking reef safe). Seachem Focus, unflavored gelatin or agar are all binding agents that can be used. My simple recipe** for food soaking antibiotics can be found below:
) I find this to be impractical for the casual hobbyist, and that my "shotgun approach" to food soaking antibiotics generally works. However, for those who wish to food soak antibiotics properly there are oral dosages listed here (Table 1): CIR 84/FA084: Use of Antibiotics in Ornamental Fish Aquaculture
Pros: Can be mixed with other medications; however effectiveness may be limited if used in the presence of an immunosuppressive (e.g. copper, Chloroquine).
Cons/Side Effects: Appetite suppression, depletes water of oxygen (so provide additional gas exchange), and antibiotics can be harsh on certain fish. Antibiotics dosed in water are also notoriously slow acting with fish.
Further reading below:
Use of Antibiotics in Ornamental Fish Aquaculture
Aquarium Medications Part 2 | Antibiotic & Antimicrobial Treatments
Related videos:
What It Treats: Bacterial infections, which are oftentimes “secondary” to preexisting parasitic (and worm) infestations.
How To Treat: Follow the directions for whatever product you are using. Always use a broad-spectrum antibiotic i.e. one that treats both gram-positive and gram-negative bacteria. It is preferable to use pharmaceutical-grade medications when treating fish. (Sources for Pharma grade: Here, here and here.) Keep in mind that with pharmaceutical-grade medications a digital scale should be used to weigh the dosage: https://www.amazon.com/dp/B0012TDNAM/?tag=humblefish-20
The following are antibiotics I recommend (in order of preference):
- Ciprofloxacin (Best administered via 1-2 hour bath treatment. Dosage is high: 250mg per gal. Repeat every 24 hours for 7 days. Methylene Blue can be added to increase efficacy.)
- Enrofloxacin (Most advanced antibiotic approved for use in tropical fish. Dosage range is 2.5 - 5 mg/L daily for 7 days; can be used in a QT or as a 5 hour bath treatment. The tricky thing about Enrofloxacin is 2.5 - 5 mg/L is a safe range for QT usage, but nitrifying bacteria will also take a hit. So, the primary reason to administer the medication in a 5 hr bath is to spare your biofilter.)
- Nitrofuracin Green Powder* (Best used in a QT with no working biofilter, as Methylene Blue contained therein can kill nitrifying bacteria.) The 30 minute bath dosage for NFG is 100mg per gallon.
- Sulfa TMP* (Trimethoprim and Sulfathiazole Sodium). 1/4 teaspoon per 10 gallons every 24 hours with a 25% water change before each treatment.
- Kanamycin + Nitrofurazone + Metronidazole* – Can be used separately, but most effective when all 3 are combined together. Kanamycin + Nitrofurazone should be dosed at the same time for maximum effectiveness. Can be used in a QT with a working biofilter. Aquarium grade alternatives: Seachem Kanaplex + Seachem Metroplex
- Other antibiotics: Neomycin (Seachem Neoplex), Sulfathiazole (Seachem Sulfaplex). Can be used separately or combined* together.
- Erythromycin (Maracyn) – Best antibiotic for treating eye infections. Minocycline (Maracyn 2) can be added to widen spectrum of treatment. Or Kanamycin (Seachem Kanaplex) is a suitable alternative to using Minocycline.
- Antibacterial bath treatments: Ruby Reef Rally (which contains acriflavine) or Methylene Blue. Also, almost any antibiotic (kanamycin, nitrofurazone, sulfathiazole, neomycin) that is normally dosed in a QT can be double dosed in a 30-35 minute bath treatment. Aerate the bath for at least 30 minutes prior, and maintain aeration + temperature throughout.
When using antibiotics, it is very important to treat for 7 - 14 consecutive days. Sometimes a fish will look & act better after just a few days; however the infection can return if you end treatment prematurely. Or sometimes you may not notice any improvement right away, as antibiotics can be notoriously slow-acting with fish. It is also best to use Pharmaceutical-grade antibiotics instead of aquarium products if possible (this short video explains why). This sticky contains dosage info for many Pharma grade medications (including antibiotics): Medication Dosing Guide
The medications listed above are primarily meant to be dosed in water. Using antibiotics in a QT environment (or bath treatment) fits within the comfort level of most hobbyists. However, the absolute best way to apply antibiotics is via intramuscular injection (which is obviously difficult to do with small fish.) The first step is to sedate the fish using MS-222 (Tricaine Methanesulfonate). Next, inject an antibiotic (e.g. enrofloxacin), or a steroid such as dexamethasone to help reduce inflammation/swelling. The injection is made into the muscle on the side of the dorsal ridge (video here), angling the needle towards the head or tail to avoid hitting any major organs below. Typically you would use a tuberculin syringe with a 27 gauge needle to draw up the solution and a 30 gauge needle to inject. After the injection is complete, place the fish in a heavily oxygenated bucket with clean saltwater and glide the fish through the water until he is revived. Dosage for Intramuscular dexamethasone varies from 1-2 mg/kg, and for enrofloxacin it varies between 6.14 to 9.69 mg/kg. For most other antibiotics the dosage ranges from 4 to 10 mg/kg. (Mg=amount of medication, kg=weight of fish)
You can also food soak antibiotics; this is especially useful for treating internal infections. Neomycin will not get absorbed by a fish’s gastrointestinal tract, thus making it an excellent antibiotic to lace in food. I’ve also had success by food soaking kanamycin. Metronidazole is another good option and can also be used to treat internal flagellates. See Table 1 (here) for other antibiotics which can be soaked in food. It is also important to use a binder to reduce loss of medication to the water through diffusion (this also makes food soaking reef safe). Seachem Focus, unflavored gelatin or agar are all binding agents that can be used. My simple recipe** for food soaking antibiotics can be found below:
- 1 tbsp food (preferably frozen food or pellets)
- 1 scoop (~ 1/8 teaspoon) of medication
- 1-2 scoops of Seachem Focus (binder)
- Several drops of saltwater or fish vitamins to wet everything down
- Stir until a medicated food slurry has been achieved
- Feed after soaking for 30 mins
- Refrigerate or freeze any leftovers for future use
- Feed daily for 10-14 days
) I find this to be impractical for the casual hobbyist, and that my "shotgun approach" to food soaking antibiotics generally works. However, for those who wish to food soak antibiotics properly there are oral dosages listed here (Table 1): CIR 84/FA084: Use of Antibiotics in Ornamental Fish AquaculturePros: Can be mixed with other medications; however effectiveness may be limited if used in the presence of an immunosuppressive (e.g. copper, Chloroquine).
Cons/Side Effects: Appetite suppression, depletes water of oxygen (so provide additional gas exchange), and antibiotics can be harsh on certain fish. Antibiotics dosed in water are also notoriously slow acting with fish.
Further reading below:
Use of Antibiotics in Ornamental Fish Aquaculture
Aquarium Medications Part 2 | Antibiotic & Antimicrobial Treatments
Related videos:
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