Tetra Troubles - Erythromycin

[Lulamae901]

Hi everyone,
Recently my fish has looked unwell. It started with what looked like a swollen lip which I thought at first must have just been an injury from bumping into something. Several days ago I noticed he now has problem areas on and around most fins. He also has some rough scale patches along the side of his tail. The other fish looks okay except for a tattered tail fin.
I’m on day 7 of API E.M. Erythromycin and Stress Coat +. I’ve been following the instructions which means I’m halfway through a 2nd round of treatment. I’m not seeing any improvements in either fish.
Does anyone have any thoughts or suggestions? It’s greatly appreciated.

5gal established Fluval freshwater with live plants, small frog, and 1 nerite. ph 6.5 Fish are several months old. No new additions or changes except current meds.

 

[SaraB]

Google neon tetra disease and see if any of the symptoms match.
The fins look like fin rot. What are your water parameters and water change schedule?

 

[Lulamae901]

The nitrates were very slightly elevated but everything else was okay. Typically I’m changing 10% weekly then doing a 50% with vacuum every couple months.
With these meds I’ve done a 25% change every other day for the last 8 days.

Google was my first stop and how I landed on treating with erythromycin. Unfortunately that doesn’t seem to be helping.