I have a 75 gal. tank with 4 silver dollars and 2 bala sharks, all young fish. I have had them for 3 weeks and they are very active fish. I have noticed that the silver dollars all have some degree of fin damage. No one in the tank appears to be nipping, so I think it is the beginning of fin and tail rot. I have been told ( by local fs, I know, I know) to use E.M. Erythromycin. My question is, as this is an anti-bacterial medication, will it kill my good bacteria? My tank was fully cycled, without fish for 4 months before I added fish and I don't want to kill my good bacteria and have to start over( not to mention harming my fish). Any help is greatly appreciated! BTW, all water parameters are close to perfect and water is crystal clear. Thanks!
Barb
Barb
