antibiotic

Hi All, thanks to everyone for your support over the years. We need your help again to solve a mystery. I was told this white gob was likely a harmless cyst, and a result of old age, but now there are 3. Two of them are big around 5-6mm and a third is very small, only 1.5mm across. (Pardon the...

All the product manuals (API, Fritz, etc) that I've read only say "Erythromycin". Is this form usable for fish or is there something else? I'm confused