FishyMagEvidence-led tank care

Formulation evidence record

Fritz Aquatics Maracyn

Bacterial infection treatment · US formulation

Shrimp

Amano, cherry, crystal and other freshwater shrimp.

Compatible

Snails

Nerite, mystery, ramshorn and other aquarium snails.

Compatible

Live plants

Rooted and floating live aquarium plants.

Caution

Marine invertebrates

Corals, anemones, starfish and marine crustaceans.

Compatible

Biological filter

The nitrifying bacteria in your filter media.

Do not use

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 publishes a species compatibility table that answers this directly: snails and other invertebrates are marked compatible. Shrimp fall under that heading.

“Snails and other invertebrates Yes”

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

Snails

Manufacturer states compatible

Named directly in Fritz’s compatibility table as compatible.

“Snails and other invertebrates Yes”

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

Live plants

Caution

Compatible with a stated cosmetic caveat — Fritz warns some plant species may yellow temporarily. Recorded as caution rather than compatible because the manufacturer attaches a visible effect to its own yes.

“Live plants including pond plants Yes, some plant species may show temporary yellowing”

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

Marine invertebrates

Manufacturer states compatible

Fritz marks both saltwater fish and coral compatible in the same table.

“Saltwater fish Yes”

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

Biological filter

Manufacturer advises against

Fritz warns the treatment may inhibit nitrifying bacteria and tells keepers to monitor ammonia and nitrite throughout. An ammonia spike during a five-day course is a foreseeable outcome, not a surprise.

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

“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
Bacterial infections, Fin rot, Body fungus, Cyanobacteria
Chemical filtration
Not stated by the manufacturer
Ingredients as stated
Erythromycin.
Active ingredients
Erythromycin

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

Record last checked August 16, 2026 · confidence medium

Check against your tank

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

Bacterial infection 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 publishes a species compatibility table that answers this directly: snails and other invertebrates are marked compatible. Shrimp fall under that heading.

  • SnailsManufacturer states compatible

    Named directly in Fritz’s compatibility table as compatible.

  • Live plantsCaution

    Compatible with a stated cosmetic caveat — Fritz warns some plant species may yellow temporarily. Recorded as caution rather than compatible because the manufacturer attaches a visible effect to its own yes.

See the manufacturer’s exact wording and sources for Fritz Aquatics Maracyn →

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

Other treatments

Seachem ParaGuardFritz Aquatics Algae Clean OutFritz Aquatics Mardel CoppersafeSeachem CupramineAPI Liquid Super Ick CureSeachem MetroPlexSeachem PolyGuardFritz Aquatics PraziCleanseAPI General CureFritz Aquatics ParaCleanseSeachem KanaPlexSeachem NeoPlexSeachem FocusSeachem StressGuardAPI MELAFIXFritz Aquatics Expel-PSeachem SulfaPlexAPI PIMAFIXFritz Aquatics Maracyn TwoFritz Aquatics Maracyn OxyFritz Aquatics FixIckFritz Aquatics Expel-FFritz Aquatics MetroCleanse

Next steps

How much Fritz Aquatics Maracyn 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 Maracyn and every other treatment compare against what you actually keep.Compare with another treatmentPut Fritz Aquatics Maracyn 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.