Fish Penicillin - Fish Pen 500mg Tablets

-25%

Fish Pen - Penicillin 500mg 30 Tablets

$59.99 $79.99

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Check The Latest Expiration Dates

Updated 05/21/2025

Looking for the freshest and most reliable fish antibiotics online? Whether you're stocking up on Fish Mox, Fish Flex, Fish Zole, or Fish Sulfa, knowing the expiration dates is essential for ensuring the effectiveness of your aquarium medication. We've created this regularly updated expiration list so you can shop confidently. Don't risk outdated meds—compare your current product with the latest fish antibiotics expiration dates from trusted sources like Thomas Labs Pets.

From broad-spectrum fish antibiotics like amoxicillin, ciprofloxacin, and doxycycline, to advanced treatments like fluconazole and metronidazole, we’ve got you covered. Make sure your fish meds are safe, current, and fully potent with the latest updates below.

Fish Antibiotics Expiration Dates

Fish Mox - Amoxicillin 500 mg 100 Capsules – Expires: 08/2027
Fish Mox - Amoxicillin 250 mg 100 Capsules – Expires: 05/2027
Fish Zole - Metronidazole 250 mg 60 Tablets – Expires: 12/2026
Fish Zole - Metronidazole 500 mg 60 Tablets – Expires: 02/2027
Fish Flex - Cephalexin 250 mg 100 Capsules – Expires: 04/2026
Fish Flex - Cephalexin 500 mg 100 Capsules – Expires: 06/2027
Fish Doxy - Doxycycline 100 mg 30 Capsules – Expires: 02/2026
Fish Doxy - Doxycycline 100 mg 60 Capsules – Expires: 06/2026
Fish Pen - Penicillin 500 mg 30 Tablets – Expires: 06/2026
Fish Pen - Penicillin 500 mg 60 Tablets – Expires: 06/2026
Fish Flox - Ciprofloxacin 500 mg 30 Capsules – Expires: 04/2027
Fish Flox - Ciprofloxacin 500 mg 60 Capsules – Expires: 04/2027
Fish Sulfa - Sulfamethoxazole & Trimethoprim 960 mg 30 Tablets – Expires: 12/2028
Fish Sulfa - Sulfamethoxazole & Trimethoprim 960 mg 60 Tablets – Expires: 12/2028
Fish Zithro - Azithromycin 250 mg 30 Tablets – Expires: 06/2027
Fish Cin - Clindamycin 150 mg 100 Capsules – Expires: 08/2026
Reef Flux - Fluconazole 200 mg 10 Capsules – Expires: 02/2027

Aqua Lab

Thomas lab

SKU: AS-10007

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Product Description
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Fish Penicillin - Fish Pen 500mg (30 Tablets) | Aquarium Antibiotic

High-Potency Treatment for Fin Rot, Gill Disease & Other Bacterial Infections

Fish Penicillin - Fish Pen 500mg (30 Tablets) is a broad-spectrum fish antibiotic designed to combat gram-positive bacterial infections in freshwater and saltwater aquariums. Each tablet delivers 500mg of penicillin, an effective treatment for fin rot, gill disease, columnaris, and septicemia. This trusted aquarium antibiotic ensures safe and efficient bacterial infection control without disrupting the aquatic environment.

Explore More Fish Antibiotics

Key Benefits

✔ Broad-Spectrum Antibiotic – Targets fin rot, columnaris, septicemia, and gill disease in aquarium fish.
✔ High-Potency Formula – Each 500mg tablet delivers a strong and consistent bacterial treatment.
✔ Safe for Aquarium Use – Specifically formulated for freshwater and saltwater environments, ensuring ecosystem balance.
✔ Convenient Packaging – Includes 30 tablets, ideal for single or multiple treatments.
✔ Trusted Quality – Manufactured under strict quality standards for purity and effectiveness.

Dosage Instructions

✔ Add 1 tablet (500mg) per 10 gallons of aquarium water.
✔ Repeat every 24 hours for 5-10 days, depending on infection severity.

Usage Tips & Cautions

✔ Remove activated carbon filters during treatment for maximum effectiveness.
✔ Monitor water quality and perform 20-25% water changes between doses.
✔ Not for human use.