Aquarium Medications

Updated 1-16-19

Erythromycin is a primarily gram positive antibiotic with a slightly "wider" antimicrobial spectrum to otherwise similar to penicillin.

A popular albeit often incorrectly and over recommended for fish infections. In humans Erythromycin is often used respiratory tract infections, which of coarse does not exist in fish (gills versus lungs).

During treatment Erythromycin is rapidly absorbed in a microbiologically active form into most tissues and phagocytes found in vertebrates (such as fish). Due to the often resulting high concentration of Erythromycin in phagocytes (white blood cells), Erythromycin is actively transported to the area of infection.
Over use of Erythromycin may result in muscle (including heart) and kidney damage, providing electrolytes, in particular calcium while treating with Erythromycin can aid in prevention or reversal of this damage

USE:

The primary disease pathogens for use of Erythromycin are Staphylococcus and Streptococcus (which often includes many eye and mouth infections of fish).
Occasionally these bacterial pathogens can result in fin and tail rot as well.

Erythromycin can generally be combined safely with Triple Sulfa for a more wider spectrum treatment (especially for use against Staphylococcus infections).

Another use for Erythromycin is for cloudy aquariums and cyanobacteria blooms, however Erythromycin Sulfate is much more effective for these applications (as well better for fish pathogens) and most Erythromycin (such as API) is not of this form of Erythromycin.
Sometime in 2019, "AAP Professional Aquarium Treatments" will have this preferred form of Erythromycin available for aquarium/pond use again.
Resource: AAP Professional Aquarium Treatments

Although often recommended for Columnaris and Fish Fungus, these are simply INCORRECT uses for Erythromycin.

As with ANY treatment regimen, it is extremely important to follow correct procedures that includes addressing ALL water parameters and stressors (including oxidative stress.
Please read this easy to read article and follow ALL advice given as to proper treatment regimens:
Fish Diseases | How to Treat Sick Fish

DIAGNOSTIC CHART
Please realize diagnostic charts are generalizations with many inaccuracies such as use for "true" mouth fungus.
Please click on the picture to enlarge for better view

FINALLY: While I strongly recommend the use of a UV Sterilizer both before and after treatment (24/7), use of this device should be discontinued during treatment with Erythromycin.

"API Erythromycin" can be purchased here (A business with professional aquarium medication experience dating back to 1978):
API Erythromycin

Sources:
*Aquarium Medications; How They Work
*Aquarium Medications; Antibiotics, Erythromycin *http://en.wikipedia.org/wiki/Erythromycin
*https://www.drugs.com/pro/erythrocin.html

Suggested other aquarium information resources & products:

Fish Diseases | How to Treat Sick Fish

*For a proven step by step method to reduce the incidence of disease in your aquarium fish:
Aquarium Fish Disease Prevention; A Healthy Aquarium

AAP Hydro Sponge Filters

THE PREMIUM Aquarium Sponge Filter with as much as 5 TIMES the bio and mechanical capacity of commonly sold Chinese knock offs!!
Definitely worth the extra $1-3

*For Replacement UVC Bulbs to keep your UV Sterilizer (such as a TMC Vecton or Advantage UV) in peak performance, please visit this resource:
UV Bulbs

*Submersible Quartz & Digital Titanium Heaters

*Economy Submersible Aquarium, Vivarium, or Terrarium Fountain Pumps
Pumps ranging from 160, 238, 238 Gallons per Hour (gph)

Labels: Aquarium, Columnaris, Erythromycin, Eye Infection, Fish, fungus, mouth fungus, Pond, Sick Fish, Staphylococcus, Streptococcus

Revised 3/20/23

This article is copied in part courtesy:
Aquarium Medications 2, Antibiotics/ Anti-microbials

Nitrofurazone also known as Nitrofural, is a broad-spectrum bactericidal drug, with some anti-protozoal activity. Nitrofurazone can be used both therapeutically (treatment) and prophylactically (prevention).

Nitrofurazone inhibits several bacterial enzymes, especially those involved in the aerobic and anaerobic degradation of glucose and pyruvate.

This antibacterial is effective for control of:
Aeromonas (Symptoms: fish have blisters forming on the skin that are full of a clear to yellowish fluid. The blisters may turn into large sores.), Vibrio and related bacterial species.
AND partly effective Flexibacter/Columnaris (Symptoms: Fuzzy, thin, white coating on the body and fins. Looks like a fungus) it works well with Kanamycin (best used in AAP Yellow Powder) for difficult incidences of this pathogen.

Nitrofurazone/ Nitrofural (AAP Yellow Powder) is particularly useful for control of minor topical skin infections of freshwater & marine fish that have not become systemic.
As well, Nitrofurazone is effective for surface skin infections of Streptococcus iniae which may appear as a milky peeling slime.
Effective as well against marine external ulcer disease and some protozoan infestations. For this reason, Nitrofurazone is a good next step treatment for wounds and other topical infections when first step treatments such as Pimafix or Melafix fail.
Nitrofurazone is also useful in treating Furunculosis found in Koi (best treated in a small "kid pool" or bathtub with a seasoned Sponge Filter).

Serious adverse reactions related to general nitrofurans are very rare in aquarium or pond fish. Acquired resistance of bacteria to nitrofurans during therapy has been rare and has not appeared on a significant scale in over 50 years of use.
Do not use in the presence of invertebrates.

TIPS

*Nitrofurazone is more effective at lower pH levels. Nitrofurazone is not Skin absorbed, so use of this Bactericidal for systemic infections is not recommended.
However Aquatronics and myself have found that Nitrofurazone combines well with Kanamycin (which is skin absorbing), and is very complimentary/synergistic to each other when used concurrently since Nitrofurazone is often effective topically for Aeromonas & Furunculosis while Kanamycin is often helpful to be combined for Columnaris.
Since these bacterial infections are often hard to differentiate by the average aquarist, this can be a good combination when unsure.

*As noted, Nitrofurazone can be combined with Kanamycin/Kanaplex to make an even more wide spectrum treatment, especially for difficult cases of Columnaris or Aeromonas.
AAP Yellow Powder is currently the best and most effective blend of Nitrofurazone (combining nitrofurazone with acriflavin) and this should be the product of choice for any serious aquarium/fish keeper looking to treat Columnaris, Aeromonas, Vibrio, or Furunculosis..
This blend of AAP Kanaplex and AAP Yellow Powder provides for an easier to use and more importantly, more synergistic and effective combination since these two medications are not used in a somewhat conflicting treatment regimen as in the Kanaplex/Furan 2 combination which is less effective due to the lack of concurrent use and lower grade nitrofurazone lowering the synergistic combination affect.

Please also beware that Carl Strohmeyer was the first to bring the nitrofurazone combination to the internet in 2005, however many parasite/plagiarizing websites have copied this method without proper accreditation to known fish guru Carl Strohmeyer.
This is wrong, and sites like this should be avoided as often they use expert sounding names such as "Labs", but in reality are not the true experts with decades of experience professionally and peer recognition for decades of such experience as with Mr. Strohmeyer. Many of these sites often are set as affiliates to shill for Amazon products that are often inferior (as compared to products such AAP Yellow Powder).
It is worthy of note, that some search engines, most notably Bing's AI experiment (which is highly inaccurate and subjective in many if not most searches), will often bring up these shill or spam sites (such as Spruce) over authoritative sites such as American Aquarium Products.

For Bettas and other smaller long tailed fish such as Guppies, as well as colder water fish such as goldfish or koi, an excellent preventative and treatment of moderate fin/tail infections, as well as ammonia poisoning, loss of color, and listlessness is AAP Nitrofuracin Green. This product safely blends Synergistic Nitrofurazone, Sulfathiazole Sodium, Methylene Blue, and NaCl.

*Nitrofurazone/Kanamycin can be combined with Metronidazole for parasitic, fungal, & bacterial infections.

DIAGNOSTIC CHART
Please realize diagnostic charts are generalizations.
Please click on the picture to enlarge for better view

"API Furan Two" (Nitrofurazone + Furazolidone) can be purchased here (A business with professional aquarium medication experience dating back to 1978):
Furan 2

OR BETTER, higher quality Nittofuarzone blend that generally only needs 1 or 2 doses:
AAP Yellow Powder; Premium Nitrofurazone Blend