Fritz Maracyn

Regular price
Sale price
Regular price
Sold out
Unit price

Maximum quantity in stock reached.

Orders placed within the next 1 hour will ship today.

Help us reduce shipping waste.

Minimum Order is $19.99

Total Cart Value: $0.00

  • Treats bacterial infections
  • Safe for aquarium plants
  • Safe for shrimp, snails, and other invertebrates

Fritz 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.

For the 10-count and 20-count boxes of Maracyn, the medication comes in individual packets where each packet treats 10 gallons of water. The 100-gram bulk container treats a total of 1,000 gallons of water and comes with a scoop for easy dosing. When treating with Maracyn, we recommend using an air stone in the aquarium, which may temporarily cause excessive foaming at the water surface.

Customer Reviews

Based on 495 reviews
A N. (Kansas City, KS, US)

Great product!

Henrik B. (Portland, OR, US)
Great for getting rid of blue green algae

Seems to do the trick

Baley N. (Seattle, WA, US)
Worked Great

Bought this due to one of my bettas getting fin rot. Used exactly as directed and my betta’s fins are unclamped and going back to normal!

Vedrick S. (Roseburg, OR, US)
Works really good!

Does what it is meant to do.

stacey H. (Portland, OR, US)

Crazy fast shipping. Thank you!