first time fin rot

[chirojosh]

I have a 75g, thats been setup and cylced for a few months. I had put a small 3" niger in about 2 months ago(Qt's first). Just recently I added a 12" blackedge moray eel, that was in QT. the niger hides/sleeps in a fake coral I have. The next morning I noticed that coral laying on the sand. When the niger came out I seen that he had a small scrape on his side and his bottom fin was clear/opaque on a part. The next day his bottom fin was 60-70% gone, and part of his tail fin seemed to be infected as well. I removed the eel and got rid of it about 5 days ago. Since, then Ive treated the tank with API Erythromycin, Im on the 4th/last day of treatment. The niger doesnt look worse, but doesnt look better. Should I stop the meds and just go back to proper water changes etc.? The water parameters were WNL, no ammonia, no nitrite and nitrate between 5-10.

 

[b0bab0ey]

Erythromycin only treats gram-positive infections. IME, it's a very safe antibiotic to use but also slow acting. So, you might need to do a 2nd round of treatment.

If the fin rot doesn't clear up after the 2nd round, then it's possible it's being caused by something gram-negative. For that you'd need to treat with something like Minocycline.

Erythromycin & Minocycline can be safely used together if you wanted to start the gram-negative treatment now.

 

[chirojosh]

petsmart has tetracycline, and maracyn (freshwater) would one of those do?

 

[b0bab0ey]

petsmart has tetracycline, and maracyn (freshwater) would one of those do?

Erythromycin is the active ingredient used in Maracyn. If you buy the f/w version, you have to double the dosage for s/w.

Tetracycline treats both gram-positive and gram-negative, but IME it's harsh on the fish. Definitely don't mix with Erythromycin.

If you're looking for a good, all-in-one broad spectrum antibiotic (treats both gram-positive and gram-negative) I recommend Furan-2.