Fish Sulfa Forte (Fix Sulfa) SMZ/TMP 960mg Fish Antibacterial

If you previously purchased Thomas Labs Fish Sulfa Forte, FISHBIOTIC SMZ/TMP or Aqua Sulfa, here is what has changed and what remains the same:

• Dual-Action SMZ/TMP Combination

  Fix Sulfa pairs sulfamethoxazole and trimethoprim (SMZ/TMP), a combination aquarists use to help manage certain bacterial issues in ornamental fish when used as directed.

• Made in the United States

  Fix Sulfa is made in the United States by Aqua Soma Labs as the current-production version of the discontinued Fish Sulfa Forte, with fresh expiration dates on every bottle.

• Support for Common Aquarium Problems

  Aquarists commonly reach for fish sulfa tablets when dealing with symptoms associated with fin and tail rot, columnaris-type presentations, cotton wool disease, ulcer-like lesions, pop-eye, and other persistent bacterial signs in ornamental freshwater and saltwater fish.

• Helps With External and Internal Signs of Bacterial Stress

  SMZ/TMP tablets are often used in a hospital tank for visible skin sores, fin damage, and hemorrhagic septicemia, and in situations where fish show lethargy or reduced appetite alongside water-quality corrections and supportive care.

• Consistent 960 mg Tablet Strength

  Each tablet provides a consistent 960 mg format, making it easier to plan repeatable amounts across different tank sizes. Available in 30- or 60-tablet bottles.

• Intended for Ornamental Fish Use

  Fix Sulfa is intended for aquarium and ornamental fish use when used as directed, and the tablet format offers a straightforward option for hobbyists who prefer predictable, countable amounts.

• Helpful for Quarantine and Hospital Tanks

  Treating in a separate hospital or quarantine tank can help you observe fish more closely, control the amount more precisely, and reduce unnecessary exposure for healthy tank mates during treatment.

These steps follow the Fix Sulfa 960 bottle label directions for SMZ/TMP use in ornamental aquarium fish.

Quick Usage Summary:
Dissolve one (1) dose (one tablet) and add it for every 40 gallons (151 L) of water to be treated. Repeat every 24 hours with a partial water change between treatments for 5 to 10 days. Discontinue use if no improvement is noted after 5 days.

Before You Dose:

• Measure Water Volume

  Calculate actual water volume (account for substrate, decor, and fill level).

• Use a Hospital Tank

  Use a hospital/quarantine tank when possible for better control and observation.

• Remove Carbon and UV

  Remove activated carbon and other chemical media; turn off UV sterilizers during treatment.

• Boost Aeration

  Increase aeration and surface agitation; keep temperature stable.

Directions for Use:

1. Dissolve and Add the Dose

   Fully dissolve one (1) dose (one tablet) in a small cup of aquarium water, then add the dissolved dose to the treatment tank. Add one tablet per 40 gallons (151 L) of water to be treated.

2. Repeat Every 24 Hours

   Repeat every 24 hours. Perform a partial water change between treatments throughout the treatment.

3. Complete the Treatment and Watch for Progress

   Continue treatment for 5 to 10 days. Watch appetite, swimming behavior, fin condition, and any signs of stress. Discontinue use if no improvement is noted after 5 days. If fish appear worse or show severe stress, stop treatment and seek aquatic veterinary advice.

4. Post-Treatment Clean Up

   After the treatment is complete, perform a partial water change and resume normal filtration. Replace activated carbon or chemical media if you removed it, and keep monitoring water parameters for several days to confirm stability.

The Fix Sulfa 960 label states one (1) dose (one tablet) per 40 gallons (151 L), which is about 24 mg of combined sulfamethoxazole and trimethoprim per gallon. The 40-gallon row is the exact label instruction; the other rows scale that same rate. For tanks under 40 gallons you can split a scored tablet, or dissolve one tablet in a measured cup of tank water and add the matching fraction for more accuracy. Dose by your treatment tank's water volume, not the number of fish, repeat once every 24 hours for 5 to 10 days, and follow the bottle label or your aquatic veterinarian over this quick-reference chart.

What to Expect During Treatment

Pro Tip: Hospital tank treatment helps protect the display aquarium, keeps the amount consistent, and makes it easier to keep ammonia and nitrite at 0 during recovery.

Each Fix Sulfa tablet pairs sulfamethoxazole 800 mg and trimethoprim 160 mg (SMZ/TMP). Dissolved and added to aquarium water as directed, the two ingredients work together to help slow the growth of certain bacteria.

Alongside those two ingredients, each tablet includes standard ingredients that hold the tablet together and help it disperse properly in water. Aquarists use Fix Sulfa for fin and tail rot, ulcer-like lesions, columnaris, pop-eye, and other bacterial signs in ornamental freshwater and saltwater fish.