This is the 3rd phase of our 80/20 quarantine protocol that is specifically focused on the treatment of Flukes. The 80/20 QT is a multi-stage quarantine protocol that can be tailored to suit your specific livestock and the level of protection you wish to achieve.  Be sure to review phases 1 and 2 of the 80/20 quarantine along with the entire Fish Health video series to achieve the best results when quarantining fish at home. 

What are Flukes?

Flukes are parasitic flatworms (Monogeneans) that can attach themselves to a fish's gills, mouth, eyes, or body. They are extremely common and can create varying degrees of irritation but are generally not deadly. It is estimated that upwards of 90% of saltwater aquariums have Flukes and without proper identification and treatment, there is a good chance your fish have Flukes and you don't even know it. 


Why treat for Flukes if they are most often not deadly? 

Flukes will most certainly cause stress among infected fish, some cases are worse than others. In the most severe cases, you can witness body bruising, general discomfort, and head shakes or "coughing" as fish attempt to dislodge Flukes from their gills. 

If your fish's health becomes compromised for any reason, the presence of Flukes can make the situation worse and decrease that fish's chance of surviving the stress event. By eliminating Flukes, to begin with, you can effectively increase your fish's chance of long-term survival in the aquarium.  Remember, there is always a risk of something going wrong, prevention is about doing everything you can to give your fish a leg up when the unexpected should occur. So even though having Flukes is not the most threatening condition for new fish, it's still something that should be addressed during the quarantine period. 

Formalin - It Works for Flukes Too! 

During Phase 2 of our quarantine system, we described a series of Formalin baths designed to directly target Brooklynella and Uronema which are both very deadly diseases for new aquarium fish. If treatment with Formalin is part of your routine, there is no need to specifically target Flukes with an alternative method (phase 3 described below) because Formalin is a very effective treatment for removing Flukes.

You can physically see Flukes fall off the fish during treatment and will appear like small flatworms, turning white and falling off the fish as they die. During treatment, the fish may cough or act erratically as they attempt to dislodge the dying Flukes. 

Remember, Formalin is quite toxic and treatment with Formalin should not be taken lightly. If you have decided to forego treatment with Formalin for any reason, you can use this alternative approach to target Flukes using PraziPro.

Quarantine Tank

Phase 3 - How to Treat Flukes Using PraziPro

1. Complete Phase 1 - 14 day quarantine and treatment for Ich and Marine Velvet

Before treating for flukes, you want to ensure you have completed the initial 14-day quarantine process described as phase 1 of the 80/20 quarantine process. This initial 14-day quarantine should be the very first protocol that ALL new fish endure to help reduce your chances of infection with Ich or Marine Velvet.  Only after this process is complete should you proceed to treat for flukes using PraziPro.

2. Rinse Out Saltwater Mixing Bin

For any QT procedure, it is critical to be very adamant about not cross-contaminating your QT tank or saltwater mixing bins. Not only with disease and parasites but also with medications. Since this treatment is going to follow your initial quarantine, you need to rinse your saltwater mixing container very well before mixing a new batch of saltwater. 

  • Rinse the mixing bin thoroughly with freshwater
  • Fill with RO/DI water and mix a new batch of clean saltwater to match the temperature and salinity from the original quarantine. (Matching parameters minimizes stress).

3. Setup a Separate QT Tank

It is best to use a separate aquarium to perform your Fluke treatment. Using the same aquarium for both your 14-day quarantine and Fluke treatment poses a risk of cross-contamination. The necessary procedure for sterilizing and dechlorinating the same aquarium in between treatments takes time, will probably stress out the fish, and just adds more unnecessary work. Using a second, clean aquarium is inexpensive and reduces the chances of any cross-contamination. 

  • 10-gallon aquarium
  • PVC hide or some kind of cover for the fish
  • Air pump with air stone
  • Heater
  • Powerhead to oxygenate and break the surface tension

4. Fill QT Tank, Test Parameters, Rinse & Transfer Fish

Rinsing your fish in between tank transfers will avoid cross-contamination with medications or pathogens. Rinsing is easy and can be done in a small container of saltwater, just place the fish into the clean saltwater container for a few minutes in between tanks. Also, once you transfer your fish out of QT tank #1, don't forget to empty, rinse, and sterilize that aquarium for storage so it is ready to go next time. DO NOT store your QT tanks without sterilizing them. 

  1. Fill the QT tank with clean, unmedicated saltwater.
  2. Test the water parameters to verify temperature and salinity levels.
  3. Prepare a clean saltwater bath in a small container to rinse your fish.
  4. Remove fish from old QT tank #1 and place them directly into a clean saltwater bath. 
  5. Remove fish from bath and place fish into new QT tank #2 for Fluke treatment.

5. Dose PraziPro and Perform Water Changes Every 3 Days

Hikari PraziPro contains praziquantel which is the medication used to treat Flukes. 

  1. Dose the aquarium with the recommended amount of Prazi-Pro (5mL per 20 gallons of water - read instructions)
  2. Keep fish in medicated water for 3 days
  3. Remove fish into a separate container
  4. Perform 100% water change on QT tank and fill with clean saltwater
  5. Return fish into QT Tank, dose with PraziPro again
  6. Repeat the process every 3 days for a total of 9 days (3 doses of PraziPro every 3rd day with 100% water changes in between)

Caveats & Things to Consider

Sterilization During Fluke Treatment Is Not Required

When performing water changes during your Fluke treatment, complete sterilization is not required.  In other words, you don't have to bleach the tank with every single water change.  Just empty the tank, rinse it out, and fill it with clean saltwater. The adult Flukes are not able to survive in PraziPro medicated water so there is no risk of transferring parasites. The repeated treatments are simply required to kill off any eggs that might survive the initial dose. 

PraziPro Feeds Bacteria

PraziPro may cause the water to cloud up because it creates a bacteria bloom. This bacteria can take up oxygen from the water which is why using an air stone and powerhead together is so important. The 100% water changes remove that bacteria along with any waste and keep the water as clean as possible.  

PaziPro Is NOT SAFE for Wrasses

Do not use PraziPro to treat Wrasses. Use a freshwater dip instead. Good news, flukes are not super common on Wrasse species.

Severe Fluke Infestation

The process we described above in Phase 3 is a preventative treatment.  If you have a fish that has a severe infestation of Flukes, you can perform a more aggressive PraziPro treatment to kill off the Flukes. Keep in mind that PraziPro does reduce oxygen levels so keeping the water actively oxygenated is critical. 

Mixing Medications

Never mix Formalin and PraziPro or Copper. As a practical rule, mixing medications is never a safe option and you should avoid it.