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Mardel Maracyn

$ 49.00 until FREE shipping

Maracyn's active ingredient is Erythromycin. The savings come in the large 24 pack or larger over the traditional API Erythromycin. Each packet treats 10 gallons.

Provides relief from bacterial infections such as body fungus, gill disease 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 we don't currently carry.

Customer Reviews

Based on 35 reviews
Always good to have on-hand

I had a congo tetra breathing heavier than normal and stopped eating, treated the tank as per instructions. His breathing slowed back to normal day 4 of treatment and started eating again about 3 days after treatment. Just because you think things are looking good after only 2 or 3 treatments, you HAVE to treat for 5 days. Otherwise you may have it come back and have to start at zero again.

Good medicine

I followed the instructions and it cured my guppies of fin rot. Nerite snails in the tank were fine with it.

Removed Blue-Green Algae

I have been fighting blue-green algae for months now and finally used this stuff. It was 100% gone within two days!

I was in need

I made the mistake of buying some new fish from a big box pet store and they got very sick very fast. It soon became obvious they were never treated for parasites. I had to act fast this was the only store online that had the medication that was recommended for my situation. Which was also from an Aquarium Co-Op youtube video. The shipping was fast being more than 2k miles away I was impressed. Today my tetras are happy and healthy. Would recommend this product and this store.

Big thanks to Aquarium Co-Op

Works great. Shout out to Aquarium Co-Op for all their testing and finding great products. Keep the trio in your fishroom!