Fish antibacterials for sick aquarium fish

Ragged fins, red sores, or fish gasping at the surface? Tap what you see to find the matching Aqua Soma Labs Fix treatment, then dose it by the gallons in your tank.

What do you see in the tank?

Showing all nine treatments.

Ships the same or next business day
Dose chart for every tank size
Aqua Soma Labs Fix line

Shop fish antibacterials

The symptom filter shows common choices, not a diagnosis. Rule out ich, velvet, flukes, and fungus first: antibacterials don't treat them. How to choose a fish antibacterial

Where bacterial infections show first

Read the signs before you dose

Bacterial infections usually show in three places first: the fins, the skin, and the gills. Each guide below covers what to look for, what to rule out, and which Fix treatments fit.

Label dose for every Fix product

Every Fix product is dosed by the volume of water you treat, once every 24 hours. Sulfa is the outlier: one tablet covers 40 gallons.

Treatment	Active ingredient	Strength	Label dose	Course
Fish Mox	Amoxicillin	250 or 500 mg capsules	250 mg per 10 gal	5 to 10 days
Fish Flex	Cephalexin	250 or 500 mg capsules	250 mg per 10 gal	5 to 10 days
Fish Pen	Penicillin V	500 mg tablets	1 tablet per 20 gal	5 to 10 days
Fish Doxy	Doxycycline	100 mg tablets	1 tablet per 15 gal	5 to 10 days
Fish Zithro	Azithromycin	250 mg tablets	1 tablet per 10 gal	5 to 7 days
Fish Flox	Ciprofloxacin	500 mg capsules	1 capsule per 10 gal	5 to 10 days
Fish Sulfa Forte	Sulfamethoxazole and trimethoprim	960 mg tablets	1 tablet per 40 gal	5 to 10 days
Fish Cin	Clindamycin	150 mg capsules	1 capsule per 10 gal	5 to 10 days
Fish Zole	Metronidazole	250 or 500 mg tablets	250 mg per 10 gal	5 to 10 days, max 10

Fish Mox or Fix Mox? The names, explained

Most aquarists search for fish antibacterials by names like Fish Mox, Fish Flex, and Fish Doxy. The bottles we stock are the Aqua Soma Labs Fix line: Fix Mox, Fix Flex, Fix Doxy, and so on. Each one carries the same active ingredient and strength as the name you searched for, and we show both names on every product so there's no guessing.

Forte usually means the stronger capsule or tablet, for example 500 mg amoxicillin instead of 250 mg.

Before the first dose

Set up a hospital tank with dechlorinated water at the same temperature, a sponge filter, and an air stone.
Remove carbon, resins, and UV. They pull antibacterials out of the water.
Measure the real water volume and dose for that, not for the number of fish.
Plan the full course with a partial water change before each daily dose.

Buying fish antibacterials online

Can I buy fish antibacterials at Tractor Supply, PetSmart, or Amazon?

Sometimes. Local and marketplace stock changes often, and listings mix strengths, tablets, and capsules. We keep all nine Fix products in stock with the strength and count stated plainly.

How fast do you ship?

Orders leave our U.S. warehouse in Missouri the same or next business day by USPS or UPS, to addresses in the continental United States. Shipping and returns

Can I return an opened bottle?

All sales of antibacterials are final. If you receive the wrong product or a damaged bottle, email us and we'll replace it.

Who are these products for?

Freshwater and saltwater aquarium fish and ornamental pond fish. Every product we sell is labeled for aquarium and ornamental fish only.

Fish antibacterials for sick aquarium fish

Shop fish antibacterials

Fish Mox (Fix Mox)

Fish Doxy (Fix Doxy)

Fish Zole (Fix Zole)

Fish Flex (Fix Flex)

Fish Pen (Fix Pen)

Fish Zithro (Fix Zithro)

Fish Flox (Fix Flox)

Fish Cin (Fix Cin)

Fish Sulfa Forte (Fix Sulfa)