Before you treat: is this actually a bacterial infection?
Antibiotics only help true bacterial infections. A quick check first:
- Test your water first. Ammonia, nitrite, and nitrate problems cause most illness. Bad water is the #1 cause of fin rot, dropsy, and stress, and no antibiotic fixes water.
- Rule out parasites. White spots (ich) and a dusty velvet sheen are parasites; antibiotics do nothing for them.
- Use a hospital tank, never dose your main tank. Antibiotics kill the good bacteria in your filter, which spikes ammonia and can harm every fish.
- Save the fluoroquinolone for when it fits. A powerful gram-negative drug and a class worth protecting, ciprofloxacin earns a vet confirming the cause and reserving it for infections that genuinely call for it, rather than reaching for the strongest drug by default.
What fish cipro (fish ciprofloxacin) is
Fish cipro is the common name for ciprofloxacin sold for aquarium fish, and you will also see it listed as fish ciprofloxacin or simply cipro for fish. As a fluoroquinolone, it works especially well against gram-negative bacteria. The molecule is the same one, manufactured and labeled specifically for ornamental fish.
We are a licensed pharmacy with a veterinarian on staff. Our job is to sell you the right treatment, and to help you use ciprofloxacin for the right reason. A vet confirms the cause and the dose. That care is the whole point.
| Active ingredient | Ciprofloxacin (as hydrochloride) |
|---|---|
| Strength | 250 mg or 500 mg (Forte) per tablet |
| Also sold as | Fish Flox, Aqua Cipro, Fishbiotic Ciprofloxacin (same drug) |
| Drug class | Fluoroquinolone |
| Form | Tablets sealed in blister packs, open for tank dosing |
| Intended use | Ornamental / aquarium fish only |
| Availability | Prescription required; included with your order. Aquarium use only, not for human consumption. |
| Delivery to | All 50 US states, contact us for other countries |
Why blister packs, not a bottle
Each tablet is sealed in its own aluminum foil pocket, backed by foil on both sides. That keeps every dose away from moisture and light until you use it. This matters for ciprofloxacin, which is sensitive to light and moisture.
A bottle is different. Every time you open it, the tablets still inside meet air, light, and humidity again. Sealed pockets also make tampering easy to see, and U.S. regulators count blister packs as tamper-evident. Blister packs cost us more than bulk bottles. The protection is worth it.
What it treats, and what it doesn’t
Where ciprofloxacin can help
Ciprofloxacin is a strong choice against gram-negative bacteria.1 Those are the bacteria behind many of the worst aquarium infections, Aeromonas and Pseudomonas, which drive ulcers, fin rot, and the kind of body swelling people call dropsy.2 When a fish vet confirms a gram-negative infection, ciprofloxacin is often one of the most effective options, because it stops bacteria from copying their DNA.3 The drug and dose remain the vet’s decision, guided by testing.
Where it’s the wrong choice
Ciprofloxacin doesn’t treat viral, fungal, or parasitic problems. Using a powerful antibiotic when it’s not needed drives resistance, and fluoroquinolones are a class worth protecting, not reaching for by default.3 A vet should confirm the cause and, where possible, test which antibiotic fits, rather than starting the strongest drug on a guess.
Take care with your tank: like most antibiotics, ciprofloxacin can harm the good bacteria in your filter, so watch your water closely during treatment. Remove activated carbon first, because it pulls the medicine out of the water. And a fish vet should confirm the cause before you treat.
Fish cipro strengths and label rates by tank volume
Fish cipro is sold as ciprofloxacin tablets, commonly 250 mg and 500 mg (Forte). The same product is also sold as Fish Flox, Aqua Cipro, or Fishbiotic Ciprofloxacin (older brand names now largely discontinued). The quick-reference below scales a common manufacturer’s label rate from the manufacturer's label to typical tank sizes. It is the label rate for planning, not a prescription. Your fish veterinarian sets the actual dose, frequency, and duration, and fluoroquinolones like cipro deserve careful, confirmed use rather than a first guess.
| Tank volume | Label rate (ciprofloxacin) | 250 mg tablets | 500 mg tablets |
|---|---|---|---|
| 10 gallons (38 L) | 250 mg | 1 | — |
| 20 gallons (76 L) | 500 mg | 2 | 1 |
| 40 gallons (151 L) | 1000 mg | 4 | 2 |
| 60 gallons (227 L) | 1500 mg | 6 | 3 |
Dose by the water volume of your hospital or quarantine tank, not by the number of fish, and pre-dissolve each tablet. The bottle label and your aquatic veterinarian always take priority over this quick reference. Because resistance to fluoroquinolones is a serious concern, cipro is best reserved for cases a vet has confirmed rather than used first by default.
⚠ Important safety notes
- For aquarium fish only. Humans should not take it. Never take fish antibiotics yourself.
- Never dose your display tank. It can crash your biofilter and harm every fish — use a hospital tank.
- Remove activated carbon first. Carbon pulls ciprofloxacin out of the water and makes the dose much weaker.
Cost & how to get it
The prescription is written as part of your order, with no separate consultation fee. The value here is the veterinary review and honest routing: if ciprofloxacin is not the right choice for your fish, we will tell you, and we won’t fill it.
| Pack size | 250 mg | 500 mg (Forte) |
|---|---|---|
| 30 tablets | $49.99 · $1.67/tab | $64.99 · $2.17/tab |
| 100 tablets MOST POPULAR | $79.99 · $0.80/tab | $103.99 · $1.04/tab |
| 250 tablets BEST VALUE | $169.99 · $0.68/tab | $219.99 · $0.88/tab |
How your order is reviewed and shipped
Place the order for the quantity you need. Instead of a public cart-and-pay step, our pharmacy emails you to confirm your delivery address and send a secure payment link. Nothing ships until that review is complete. That review is how our pharmacy keeps eyes on every order and confirms it is intended for appropriate aquarium use. We email you at each step: once you place your order and send the form, our vet reviews it, a payment link goes out, your payment is confirmed, the order moves into processing, and a tracking link follows a few to several days later, so you never have to sit and refresh a page.
Related guides
Frequently asked questions about fish cipro
What does fish cipro treat in fish?
Ciprofloxacin is a fluoroquinolone that works well against gram-negative bacteria such as Aeromonas and Pseudomonas, behind many ulcers, fin rot, and dropsy-type cases. A fish vet should confirm the cause and choose the drug and dose, ideally guided by testing.
Is fish cipro the same as human ciprofloxacin?
The active ingredient is the same molecule, but this product is manufactured, labeled, and sold for ornamental aquarium fish only, and isn’t intended or approved for human use.
Is fish cipro safe for humans?
No. Use it for ornamental aquarium fish only, never for people. If you need antibiotics for a person, see a doctor or pharmacist. You can read our guidance on this.
Do I need a prescription?
Yes — but you don’t have to arrange it yourself; a vet writes it as part of your order. After you place an order, our pharmacy confirms your delivery details and sends a secure payment link before anything ships.
Should I remove carbon from my filter?
Yes. Activated carbon absorbs the medicine and makes it much weaker. Remove it before treating, and ask a fish vet about protecting your filter’s good bacteria.
Is fish cipro the same as Fish Flox, Aqua Cipro, or Fishbiotic Ciprofloxacin?
They are the same active drug under different brand names. Fish Flox, Aqua Cipro, and Fishbiotic Ciprofloxacin (older brands, now largely discontinued) all supplied ciprofloxacin for aquarium use. Strength and count differ between brands, so dose from the label on the bottle you actually have.
Does fish cipro come in 250 mg and 500 mg?
Yes, ciprofloxacin for fish is commonly sold as 250 mg and 500 mg (Forte) tablets, so a search for fish cipro 500mg points to the same Forte strength. Match the strength to your hospital-tank volume using the label-rate table above, and let your aquatic vet confirm.
Medical disclaimer
This site is for informational purposes only and is not veterinary advice, diagnosis, or a treatment recommendation. A licensed veterinarian should determine medication selection, prescribing, dosing, and treatment for the individual animal. Never give a dog or cat antibiotics intended for aquarium fish or another species; the wrong drug or dose can seriously harm your pet. All medications sold on this site are for animal use only and are not intended for human use or consumption.
How we reviewed this page
This product page is prepared under veterinary oversight following our editorial standards. The clinical statements — what ciprofloxacin treats and where it’s not the right choice — are checked against aquatic-veterinary references and reviewed and approved by our named fish veterinarian, Dr. Julia Bauer, before publication.
Sources & References
- Merck Veterinary Manual, "Bacterial Diseases of Fish." merckvetmanual.com (2024) Supports: gram-negative etiology of common fish infections; sensitivity-guided drug selection.
- MSU / SRAC Publication 478, "Aeromonas Bacterial Infections, Motile Aeromonad Septicemia." srac.msstate.edu (1998) Supports: aeromonads are gram-negative; exophthalmia and related signs.
- Merck Veterinary Manual, "Antibacterial Agents (Overview of Antimicrobial Therapy)." merckvetmanual.com (2024) Supports: matching drug spectrum to the confirmed pathogen; targeted vs broad choices; stewardship of fluoroquinolones.
