Formulation evidence record

Fritz Aquatics Expel-P

Internal nematode treatment · US formulation

Shrimp

Amano, cherry, crystal and other freshwater shrimp.

Compatible

Snails

Nerite, mystery, ramshorn and other aquarium snails.

Caution

Live plants

Rooted and floating live aquarium plants.

Compatible

Marine invertebrates

Corals, anemones, starfish and marine crustaceans.

Caution

Biological filter

The nitrifying bacteria in your filter media.

Conflicting

Not addressed by the manufacturer for: scaleless fish. No statement was found, so no verdict is given — that is not a clearance.

Why FishyMag says this

The manufacturer's own wording, quoted rather than paraphrased, so you can judge it yourself.

Shrimp

Manufacturer states compatible

Fritz states Expel-P is safe for plants and invertebrates and does not harm uninfected fish. This is one of the clearer invertebrate clearances in the database.

“Safe for plants and invertebrates. It does not harm the bio-filter, plants, other invertebrates or uninfected fish.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

Snails

Caution

Fritz clears invertebrates generally, then carves snails out: some species may be temporarily affected. That qualifier is the reason this is not recorded as compatible — a blanket invertebrate claim does not override the manufacturer’s own exception.

“Safe for plants and invertebrates. Some snail species may be temporarily affected.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

Live plants

Manufacturer states compatible

Fritz states the product does not harm plants.

“Safe for plants and invertebrates. It does not harm the bio-filter, plants, other invertebrates or uninfected fish.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

Marine invertebrates

Caution

Cleared broadly, but Fritz notes tube worms and feather dusters may be negatively affected — worth knowing before dosing a reef system.

“Tube Worms and Feather Dusters may be negatively affected.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

Biological filter

Sources disagree

Fritz says it does not harm the bio-filter in one place and warns that treatment may inhibit nitrifying bacteria in another. Monitor ammonia and nitrite through the course regardless of which reading you favour.

Contains levamisole hcl, with a source-linked caution associated with this group. This raises a flag—it is not the basis of the verdict above.

“It does not harm the bio-filter, plants, other invertebrates or uninfected fish.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

“Treatment may inhibit nitrifying bacteria. Monitor ammonia and nitrite levels during treatment.”

manufacturer page · fritzaquatics.com · checked August 16, 2026

Product details

Manufacturer states it treats: Camallanus worms, Internal nematodes, Detritus worms
Chemical filtration: Not stated by the manufacturer
Ingredients as stated: Levamisole HCl.
Active ingredients: Levamisole HCl

manufacturer page · fritzaquatics.com · checked August 16, 2026

Record last checked August 16, 2026 · confidence high

Check against your tank

Change what is in your tank to see how the answer moves.

1 Choose the treatment

Internal nematode treatment · US formulation

2 Select everything in the tank

Assuming a common community tank. Change the selection, or save your tank so every page answers for it.

Permitted, but with conditions.

The manufacturer stops short of clearing this for something in your tank. Read the detail below before you dose.

This answers for the assumed selection above, not a tank you have described. Adjust it if it is not yours.

ShrimpManufacturer states compatible
Fritz states Expel-P is safe for plants and invertebrates and does not harm uninfected fish. This is one of the clearer invertebrate clearances in the database.
SnailsCaution
Fritz clears invertebrates generally, then carves snails out: some species may be temporarily affected. That qualifier is the reason this is not recorded as compatible — a blanket invertebrate claim does not override the manufacturer’s own exception.
Live plantsManufacturer states compatible
Fritz states the product does not harm plants.

See the manufacturer’s exact wording and sources for Fritz Aquatics Expel-P →

No evidence found means no manufacturer statement was found — not that the product is safe. FishyMag does not diagnose disease or recommend treatments.

Next steps

How much Fritz Aquatics Expel-P for my tank?Scales the label ratio to your real water volume, with the manufacturer wording beside the answer.Check against my tankSee how Fritz Aquatics Expel-P and every other treatment compare against what you actually keep.Compare with another treatmentPut Fritz Aquatics Expel-P beside up to three alternatives, group by group.Work out your real water volumeDose against the water your tank holds, not the number on the box.

FishyMag reports what manufacturers say, quoted and linked. It does not diagnose illness or recommend a treatment, and it never infers that a product is safe from the absence of a warning — where no statement exists, it says so.

Formulations change. Always read the label on the bottle in your hand, and contact the manufacturer if your tank contains anything valuable or unusual.