Fix Mox (Fish Mox) Amoxicillin Capsules - Fish & Bird Antibiotic 250 mg / 500 mg
Fix Mox 250 mg and 500 mg (often called Fish Mox in the hobby community) is a trusted, broad-spectrum fish and bird antibiotic in capsule form for ornamental aquarium fish and non-food pet birds. This amoxicillin fish antibiotic from the Aqua Soma Labs Fix range helps manage common bacterial problems such as dropsy (body swelling), fin and tail rot, red streaks, gill disease and skin ulcers in both freshwater and saltwater aquariums. Under the guidance of an avian veterinarian, the same capsules may also be used as part of an amoxicillin for birds plan for selected bacterial issues in pigeons and other pet birds.
Amoxicillin is a beta-lactam antibiotic in the penicillin family that interferes with bacterial cell wall formation, helping stop susceptible bacteria from multiplying and limiting the spread of infection. It is particularly active against many Gram-positive and some Gram-negative bacteria associated with common aquarium problems such as fin and tail rot, ulcerative lesions and certain gill infections when used as directed.
Fix Mox supplies 250 mg or 500 mg amoxicillin per capsule, giving hobbyists flexible options whether they are treating a small hospital tank, a larger community aquarium or, with veterinary input, a busy loft or aviary. For aquarists searching for a reliable Fish Mox replacement or modern alternative to older Aqua Mox products, Fix Mox delivers fresh stock with clearly labeled strengths for straightforward dosing.
Important Notice: This product is intended for aquarium and ornamental fish and pet birds only. It is not for human consumption or for animals used for food. We do not sell or recommend this product for human use.
Use Fix Mox when you notice early signs of bacterial stress in fish, such as lethargy, bulging eyes (pop-eye), red streaks, open sores, rapid breathing or unexplained body swelling. In birds, Fix Mox should only be used when an avian veterinarian has specifically recommended amoxicillin for a suspected bacterial problem. Addressing potential infections early with appropriate amoxicillin treatment, together with good water quality, suitable housing and professional guidance when available, helps your fish and birds maintain a stable, healthy aquarium or aviary.
What Are the Benefits of Fix Mox (Fish Mox) Amoxicillin 250 mg / 500 mg for Fish & Birds?
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Broad-Spectrum Support for Common Fish Infections
Fix Mox (Fish Mox) provides broad-spectrum amoxicillin coverage for ornamental fish, helping manage bacterial issues such as dropsy (body swelling), fin and tail rot, red streaks, gill disease and skin ulcers in both freshwater and saltwater aquariums when used as directed.
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Helps With External and Internal Bacterial Problems
The amoxicillin in Fix Mox can be used as an amoxicillin fish antibiotic for external signs like frayed fins, open sores and red patches, as well as internal infections that cause swelling, lethargy or loss of appetite in a hospital tank setting.
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Flexible 250 mg and 500 mg Capsule Strengths
Each capsule supplies either 250 mg or 500 mg amoxicillin, making it easy to scale dosing from smaller quarantine tanks to larger community systems. Hobbyists can follow typical guidelines of 250 mg per 10 gallons or 500 mg per 20 gallons of water, or consult an aquatic veterinarian for tailored advice.
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Easy to Use for Fish and Vet-Directed Bird Treatments
For fish, capsule contents dissolve quickly in tank water so medication spreads evenly and reaches shy or hiding fish. Under avian veterinary guidance, capsules can also be opened and carefully mixed into soft food or drinking water for selected pet birds.
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Ideal for Hospital Tanks and Quarantine Setups
Fix Mox works best in a separate hospital or quarantine tank, where you can remove carbon and UV, maintain stable water quality and keep a close eye on affected fish without exposing healthy tank mates or sensitive invertebrates to unnecessary antibiotics.
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Modern Alternative to Discontinued Fish Mox & Aqua Mox
Many hobbyists now reach for Fix Mox as their go-to Fish Mox replacement when older Fish Mox or Aqua Mox brands are no longer available. Clearly labeled strengths and fresh stock make it easier to match the dose to your aquarium or vet-directed bird treatment plan.
How to Dose & Use Fix Mox (Fish Mox) Amoxicillin 250 mg / 500 mg for Fish & Birds
Directions for Use:
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Set Up a Separate Treatment Area
Whenever possible, move sick fish to a dedicated hospital or quarantine tank before dosing Fix Mox. Remove activated carbon and turn off UV sterilizers so they do not strip the amoxicillin from the water. Perform a 20–25% partial water change before the first dose to improve water quality and reduce stress on fish.
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Dose for Fish Aquariums
Follow the label-style guideline of 250 mg amoxicillin per 10 gallons (38 L) of water or 500 mg amoxicillin per 20 gallons (76 L). Open the capsule, mix the contents in a small cup of aquarium water, then distribute the solution evenly around the hospital tank. Repeat the dose every 24 hours for 5–10 days, making a partial water change between treatments. If there is no improvement after about 5 days, or if fish appear worse, discontinue treatment and seek aquatic veterinary advice. This is the standard Fix Mox / Fish Mox dosage many aquarists use for amoxicillin fish antibiotics.
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Use in Pet Birds (Under Veterinary Guidance)
Fix Mox can be used in pigeons and other non-food pet birds only under the direction of an avian veterinarian. Your vet will determine the correct mg-per-kg dose, how often to give it and how long the course should last. Capsules are usually opened and mixed with soft food or drinking water so the full prescribed dose is taken, but you should follow your vet’s exact instructions rather than guessing.
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Maintain Water Quality & Complete the Course
Throughout treatment, monitor ammonia, nitrite and temperature closely and keep aeration strong in the hospital tank. Continue Fix Mox for the full recommended course unless an aquatic or avian veterinarian advises otherwise; stopping early can allow symptoms to return. After the course, perform a partial water change and then replace activated carbon or other chemical media to remove any remaining medication and help restore water clarity and biological balance.
Pro Tip: Treat sick fish in a separate hospital tank instead of the main display whenever you can. This helps protect your display aquarium’s biofilter and sensitive invertebrates while you focus Fix Mox treatment where it is needed most.
What Makes Fix Mox (Fish Mox) Amoxicillin 250 mg / 500 mg Effective?
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Active ingredient: Amoxicillin Trihydrate (250 mg or 500 mg per capsule)
Fix Mox contains amoxicillin, a broad-spectrum beta-lactam antibiotic in the penicillin family. Amoxicillin works by interfering with bacterial cell wall formation, which helps stop susceptible bacteria from multiplying and supports control of common Gram-positive and some Gram-negative bacteria linked with fin and tail rot, skin ulcers, red streaks and certain gill infections in ornamental fish when used as directed.
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Inactive ingredients:
Each capsule also contains pharmaceutical excipients that help keep the amoxicillin stable on the shelf and allow the capsule contents to disperse and dissolve properly when opened into aquarium water or mixed with soft food for birds under veterinary guidance.
Side Effects & Safety Tips for Fix Mox (Fish Mox)
When used as directed, Fix Mox is generally well tolerated in ornamental fish and non-food pet birds. As with any amoxicillin or penicillin-family product, incorrect dosing, prolonged use or use in stressed animals can increase the risk of side effects and contribute to antibiotic resistance.
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Fish: Amoxicillin-based fish antibiotics may cause temporary stress or hiding behavior, mild water cloudiness and reduced appetite during treatment. If fish show severe distress such as rapid gill movement, loss of balance, gasping at the surface or lying on the bottom, stop treatment, improve aeration with clean, dechlorinated water and seek aquatic veterinary advice.
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Birds: When amoxicillin is mixed with food or drinking water, some birds may develop decreased appetite, loose or changed droppings and lethargy, especially if the dose is too high or the bird is sensitive. If your bird appears fluffed up, inactive, has difficulty breathing or stops eating, discontinue use and contact an avian veterinarian immediately.
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Invertebrates: Do not use Fix Mox in display tanks that contain shrimp, snails or other invertebrates, as strong antibiotics may harm them or disrupt the tank’s ecosystem. Whenever possible, move affected fish to a separate hospital or quarantine tank for treatment.
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Safe use in your system: Treat fish in a hospital or quarantine tank whenever you can, remove activated carbon and turn off UV sterilizers during treatment, and monitor ammonia, nitrite and temperature closely. Avoid combining Fix Mox with other antibiotics or medications unless advised by an aquatic or avian veterinarian.
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Important safety & storage: Fix Mox (Fish Mox) is intended for aquarium and ornamental fish and non-food pet birds only. It is not for human use and not for animals raised for food. People with known sensitivities to penicillins should avoid direct contact with capsule contents; wash hands after handling and consider wearing gloves if needed. Store Fix Mox capsules in their original container in a cool, dry place at 59°–86°F (15°–30°C), away from moisture, direct sunlight, children and household pets, with the lid tightly closed.
Shipping & Returns
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Refund Policy: If there’s an issue with your order, you may be able to return or exchange items within 30 days according to our store guidelines. Before sending anything back, please review our refund policy carefully.
FAQs About Fix Mox (Fish Mox) Amoxicillin 250 mg / 500 mg for Fish & Birds
What is Fix Mox (Fish Mox) used for in fish and birds?
Fix Mox (amoxicillin 250 mg / 500 mg) is a fish and bird antibiotic used by hobbyists to help manage bacterial issues such as dropsy (body swelling), fin and tail rot, red streaks, pop-eye, skin ulcers and certain gill infections in ornamental fish, and to support veterinarian-directed treatment plans for selected bacterial problems in non-food pet birds.
Is Fix Mox the same as Fish Mox or Aqua Mox?
Fix Mox is an amoxicillin-based fish antibiotic similar to older products sold as “Fish Mox” or “Aqua Mox.” It uses the same type of active ingredient for similar aquarium bacterial problems, but it is a different brand, so always follow the Fix Mox label directions for dosing and duration.
How do I know if my fish might need a fish amoxicillin antibiotic?
Watch for signs such as frayed or rotting fins, red or white ulcers, red streaks in the fins or body, bulging eyes (pop-eye), labored breathing or listless behavior that does not improve with good water quality and husbandry. A fish veterinarian or experienced aquarist can help confirm whether a bacterial infection is likely and whether amoxicillin treatment is appropriate.
Can I use Fix Mox in my main community or reef tank?
It is best to treat sick fish in a separate hospital or quarantine tank instead of the main aquarium. Fix Mox and other amoxicillin fish antibiotics are not recommended for reef tanks or setups with shrimp, snails, corals or other invertebrates, because strong antibiotics may harm them or disrupt beneficial filter bacteria.
How long should I treat with Fix Mox?
For fish, many hobbyists follow label-style guidelines of dosing once every 24 hours for 5–10 days, using approximately 250 mg per 10 gallons (38 L) or 500 mg per 20 gallons (76 L), or as advised by an aquatic veterinarian. Birds should only receive Fix Mox for the dose and duration prescribed by an avian vet.
Is Fix Mox safe for pet birds, and can I treat more than one bird?
Fix Mox can be used in pigeons and other pet birds only under the direction of an avian veterinarian, who will calculate the mg-per-kg dose and decide whether to treat a single bird or an entire loft or flock. Never guess bird dosages or add capsule contents to communal water without professional guidance.
Will Fix Mox affect beneficial bacteria in my aquarium?
Any broad-spectrum fish antibiotic, including amoxicillin for fish, can affect beneficial bacteria if used in the main tank. Using a hospital tank, monitoring ammonia and nitrite, and performing partial water changes during and after treatment helps protect the biofilter while Fix Mox is in use.
Can Fix Mox treat fungal, viral or parasitic infections?
No. Fix Mox (Fish Mox) is an amoxicillin fish and bird antibiotic that targets certain bacterial infections only. It is not effective against fungi, viruses or parasites such as ich, flukes or worms, so fungal, parasitic or viral problems should be treated with other medications chosen with help from an aquatic or avian veterinarian.
Can I combine Fix Mox with other medications?
Avoid combining Fix Mox with other fish medications, especially additional antibiotics, unless an aquatic or avian veterinarian specifically recommends it. Mixing treatments can stress fish, alter water chemistry and make it harder to tell which product is working or causing side effects.
Is Fix Mox the same amoxicillin humans take?
No. Fix Mox is formulated and packaged for aquarium fish and pet birds only and has not been evaluated or approved for human use. It must never be used as a substitute for human medication or taken without a prescription from a human healthcare professional.
More Fish & Bird Antibiotics
Need another aquarium fish or pet bird antibiotic? Explore our Fish & Bird Antibiotics Collection for more Fix line and related treatments.
Looking for dosing and water-care advice? Visit the Fish & Bird Antibiotics Blog for practical guides and treatment tips.
