Expiration Date: Fix Mox 500 – EXP: 8/2027 Fix Mox 250 – EXP: 5/2027 Fix Flex 500 – EXP: 6/2027 Fix Flex 250 – EXP: 4/2026 Fix Doxy 100 - 30 – EXP: 2/2026 Fix Doxy 100 - 60 – EXP: 6/2026 Fix Flox 500 – EXP: 4/2027 Fix Pen 500 – EXP: 6/2026 Fix Sulfa 960 – EXP: 12/2028 Fix Zithro 250 – EXP: 6/2027 Fix Zole 500 – EXP: 2/2027 Fix Zole 250 – EXP: 12/2026 Fix Cin 150 – EXP: 8/2026 Reef Flux 200mg – EXP: 2/2027 Expiration Date: Fix Mox 500 – EXP: 8/2027 Fix Mox 250 – EXP: 5/2027 Fix Flex 500 – EXP: 6/2027 Fix Flex 250 – EXP: 4/2026 Fix Doxy 100 - 30 – EXP: 2/2026 Fix Doxy 100 - 60 – EXP: 6/2026 Fix Flox 500 – EXP: 4/2027 Fix Pen 500 – EXP: 6/2026 Fix Sulfa 960 – EXP: 12/2028 Fix Zithro 250 – EXP: 6/2027 Fix Zole 500 – EXP: 2/2027 Fix Zole 250 – EXP: 12/2026 Fix Cin 150 – EXP: 8/2026 Reef Flux 200mg – EXP: 2/2027

Fish Penicillin

Fish Penicillin 500mg – Trusted Aquarium Antibiotic Capsules

Fish Penicillin 500mg is a broad-spectrum antibiotic used to treat gram-positive bacterial infections in aquarium fish. Ideal for managing fin rot, gill disease, and ulcerative conditions, penicillin remains a proven solution for aquarists dealing with early or stubborn bacterial outbreaks. Whether you’re using Fishbiotic Penicillin or Fish Pen capsules, you can rely on its effectiveness for both freshwater and marine systems.

At FishAntibiotics.us, we offer high-quality Fish Penicillin in 500mg doses, commonly labeled as Fish Penicillin 500mg, Fish Penicillin 250 mg, or Fishbiotic Penicillin 500mg. No prescription is required and we ship directly across the U.S. for fast delivery and reliable treatment.

Why Use Fish Penicillin?

✅ Trusted gram-positive antibiotic with broad-spectrum activity
✅ Commonly used for ulcers, gill infections, and fin rot
✅ Available as Fish Penicillin, Fishbiotic Penicillin, and Fish Pen
✅ Safe for both saltwater and freshwater tanks
✅ Sold for aquarium use only – no prescription needed

Common Applications

Columnaris and bacterial skin infections
Ulcers, wounds, and mouth rot
Post-quarantine bacterial control
Red body lines or bacterial septicemia

FAQs – Fish Penicillin (Fishbiotic Penicillin)

What is Fish Penicillin used for?

Fish Penicillin is used to treat gram-positive bacterial infections in aquarium fish. It’s effective for gill disease, fin rot, and red streaking.

What is Fishbiotic Penicillin?

Fishbiotic Penicillin is a brand of fish antibiotics containing penicillin as the active ingredient. It is available in both 250 mg and 500 mg doses.

Is this the same as Fish Pen?

Yes. Fish Pen is a common abbreviation for Fish Penicillin. It’s often sold as Fish Penicillin 500mg or 250mg depending on strength.

Can I buy Fish Penicillin near me?

Many local suppliers no longer stock Fish Penicillin. FishAntibiotics.us offers fast shipping without requiring a prescription.

Is Penicillin safe for all fish?

When dosed correctly, penicillin is safe for most aquarium species. Always monitor water quality and remove carbon filters during treatment.

Shop Related Fish Antibiotics

Order Fish Penicillin 500mg capsules today and treat your aquarium fish with proven, trusted antibiotic support. Ships fast. No vet script required.