Fritz Expel-P

  • Use for Nematodes, Roundworms, Nodular Worms, and Hookworms
  • Can be Used As a Coral Dip

  • Safe for Plants and Invertebrates

  • Easy to Measure Packet Dosing System

  • Safe for Fresh and Saltwater Systems

About Fritz Expel-P

Fritz Expel-P is an anthelmintic (deworming) medication and immunostimulant agent. It is safe to use in both freshwater and saltwater aquaria and is effective against many internal parasites, especially nematodes, when used as directed. It does not harm the bio-filter, plants, other invertebrates or uninfected fish. As an added benefit, it boosts the immune competence of fish.

Fritz Expel-P is effective against Nematodes, Roundworms, Nodular Worms, and Hookworms. Symptoms can include worms visibly protruding from the anus of the fish, wasting, abdominal bloating, disinterest in food, or rapid breathing or gasping, Can also be used as a coral dip to treat for flatworms and pest nudibranchs.

Expel-P does not treat Cestodes (tapeworms) or Trematodes (flukes). For these parasites, try Fritz ParaCleanse.

Active ingredient: Levamisole HCl

Directions & Dosage

Standard Treatment: Use 1 packet Expel-P per 10 gallons (38 L) of water. Perform a 25% water change taking care to remove excreted worms/parasites after 24 hours. Repeat the treatment one week later to prevent reinfection. Repeat weekly treatments as necessary. See below for instructions on treating tanks smaller than 10 gallons.

Coral Dip Directions: Use three packets Expel-P per two gallons (8 L) of salt water. Place affected corals into dip for up to 30 minutes with adequate water flow to assist in worm removal. Once worms stop falling off, the coral can be returned to display or quarantine tank. Treatment does not affect eggs - remove manually or repeat treatments after hatching. Treatment can be repeated once per week, up to three times.

  • For best results, use Expel-P® in a quarantine tank
  • Remove carbon and other chemical filtration during treatment, maintain adequate water flow or aeration
  • Discontinue use of skimmer and UV sterilizers during treatment
  • The active ingredient is light sensitive; turn off aquarium lights during first 24 hours of treatment
  • No contraindications: can be used with all of our other products and meds
  • Safe for use with invertebrates; some snail species may become temporarily affected, but will recover
  • Safe for use with plants
  • Will not color or cloud aquarium water
  • Expel-P does not inhibit nitrifying bacteria, and will not impact the biofilter. If ammonia or nitrite is a concern, detoxify during treatment with Fritz A.C.C.R. or Fritz Complete
  • Overdosed? Expel-P is very safe and should not have any adverse effects. Perform a water change if distress is observed

ACTIVE INGREDIENT: Each packet contains 113 mg levamisole hydrochloride.

Note: KEEP OUT OR FREACH OF CHILDREN. FOR AQUARIUM USE ONLY. Consult a veterinarian or fish expert for assistance in diagnosis of disease causing organisms and treatment options.


Treating an aquarium less than 10 gallons? Watch our instructional video below!


Size Treats Item Number
10 ct 100 gal 90000
20 ct 200 gal 90001



See below for frequently asked questions regarding Fritz Expel-P.

  • How do I use dry medications in tanks smaller than 10 gallons?

    Dividing up our powder packets accurately for use in smaller tanks can be tricky, and to get the proper dose we recommend making a concentrated solution that is much easier to measure. We've outlined the process in the video below (or linked here) to help.


    Some example recipes:

    For a 5 gallon aquarium: mix/dissolve one packet mixed in 1/2 cup of water from the aquarium. One 5 gallon dose is equal to 1/4 cup of solution.

    For a 1 gallon aquarium: mix/dissolve one packet in 2.5 cups of water from the aquarium. A 1 gallon dose is equal to 1/4 cup of solution. 

    For tanks in between the previous options, add the amount of 1 gallon doses equal the gallon size of your tank.

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