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Fritz (Mardel) Maracyn 8 count


Regular price $11.99

No Shipping Store Pickup Only.

Maracyn's active ingredient is an antibiotic called erythromycin. Each packet treats 10 gallons. 

It provides relief from bacterial infections such as body fungus, gill disease, fin rot and popeye in fresh and saltwater aquariums.

Mardel Maracyn® is a specially compounded broad-spectrum antibiotic (erythromycin) which has been shown to be effective against a number of pathogenic bacteria associated with ornamental fish disease. It was developed for complete but gradual dissolution in water. It is primarily effective against gram-positive pathogenic organisms. Symptoms of clamped fins, swollen eyes, heavy or rapid breathing, patchy coloration, change in swimming behavior or corner-hiding can be signs of possible bacterial infection.

All suspected bacterial infections should be treated immediately.

Mardel Maracyn® is non-toxic to invertebrates such as snails and shrimp. 

Don't confuse this with Maracyn 2, which isn't the same medication and is not a product we currently carry.

Customer Reviews

Based on 1 review
Derek Diaz
Very effective

I bought Maracyn to treat what appeared to be a bacterial infection killing my neon tetras (that I had purchased at a big box store - a mistake). I lost a few tetras before the Maracyn could start working, but it stopped the infection in its tracks. All the other tetras are happy & healthy. It also didn’t harm my snails, shrimp, or plants.
If you have a 30 gallon or larger tank, you’ll definitely need the larger pack.