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Fish cephalexin 250 mg – Fix Flex fish antibiotic, 30-count bottle
Fish cephalexin 250 mg – Fix Flex fish antibiotic, 100-count bottle
Fish cephalexin 500 mg – Fix Flex fish antibiotic, 30-count bottle
Fish cephalexin 500 mg – Fix Flex fish antibiotic, 100-count bottle

Fish Flex (Fix Flex) Cephalexin 500mg & 250mg Fish Antibacterial

Price range: $19.95 through $49.99
In stock

Fix Flex by Aqua Soma Labs contains cephalexin and is labeled for treating fin rot, ulcers and bacterial skin infections in ornamental freshwater and saltwater fish.

Shipping: $5.99 flat rate, free on orders of $49 or more. Ships to US addresses within 1–2 business days; delivery typically 2–5 business days after shipping. Details

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Description

Fix Flex – Cephalexin for aquarium fish

Fix Flex by Aqua Soma Labs contains cephalexin and is labeled for treating fin rot, ulcers and bacterial skin infections in ornamental freshwater and saltwater fish.

Available as: 250-mg (30 Count), 250-mg (100 Count), 500-mg (30 Count), 500-mg (100 Count).

Before you treat

  • Follow the dosing directions printed on the bottle label.
  • Treat in a separate hospital or quarantine tank where possible.
  • Remove activated carbon from the filter during treatment and keep up regular water changes.
  • Complete the full course, even if fish look better sooner.

For ornamental aquarium fish only. Use in pet birds only under a veterinarian’s direction. Not for human use and not for food-producing animals. Keep out of reach of children.

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Fix Flex questions

What is Fix Flex used for?

Fix Flex contains cephalexin. Its label lists it for fin rot, ulcers and bacterial skin infections in ornamental freshwater and saltwater aquarium fish.

How do I know my fish needs an antibiotic?

Test the water first (ammonia, nitrite, nitrate and temperature): many symptoms come from water quality, parasites or fungus rather than bacteria. Our guide How to choose an aquarium antibiotic explains the signs.

How do I use it?

Follow the dosing directions on the product label. Treat in a separate hospital tank where possible, remove activated carbon from the filter during treatment, and finish the full course.

Can I combine it with other medications?

Don’t combine different antibiotics or other medications in the same tank unless the product labels or an aquatic veterinarian say it’s safe.

Can people or food animals use it?

No. It is sold for ornamental aquarium fish only. It is not for human use and not for fish or animals raised for food.

Last reviewed: November 2026

Additional information

Weight N/A
Strength & Count

250-mg (30 Count), 250-mg (100 Count), 500-mg (30 Count), 500-mg (100 Count)

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