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Fish Flex (cephalexin)

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Product Overview

How To Use

What’s in it?


Questions & Answers

Product Description

Fish Flex is a comprehensive antibiotic that uses cephalexin to treat a large variety of bacterial infections in fish. It is useful in treating many diseases associated with pathogenic bacteria. *Caution : Not for Human Use.  

Who is Fish Flex (cephalexin) for?

For use in ornamental and aquarium fish.

Why use Fish Flex (cephalexin)?

Fish Flex offers cephalexin monohydrate in a water-soluble formula for broad-spectrum protection against a large variety of bacterial infections of non-specific origin.

How does Fish Flex (cephalexin) work?

Fish Flex treats many non-specific bacterial infections in the most multiplying and active infection stages using cephalexin, a powerful antibiotic.


Thomas Laboratories

Active ingredient(s):


How is Fish Flex (cephalexin) sold?

30 or 100 capsules in 250 mg or 500 mg strengths

What special precautions are there?

  • Keep away from children.
  • Never use in fish intended for food use. Only use in ornamental organisms and fish.
  • Only for use in aquariums.

What to do if overdose?

Contact your closest emergency animal hospital.

How can I store Fish Flex (cephalexin)?

Store at room temperature between 59°-86°F. (15°-30°C).


Add contents of one capsule (250 mg) into aquarium for each 10 gallons of water to be treated. Repeat in 24 hours. It is suggested that a partial water change be made between treatments. While treatment duration depends on type and severity of the infection, it is recommended that extended medication baths continue for a minimum of 5 days and not more than 10 days. Discontinue treatment with this medication if no improvement is noted within 5 days.

Main Ingredients


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Fish Flex (cephalexin)

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