Small Hole In Dorsal Fin

[rust81]

I am currently treating my 70L with interpet anti fungus and finrot and this is now in the 4th day. The tiger barb that i added the med for unfortunately got no better even with the med and has now died. I thought i'd better check the remaining 7 barbs and 3 neons out to see if they are all ok. Looking closely, on 2 of the barbs, i can see very small holes in their dorsal fins - nothing more than a pin prick. Should i be worried? Should i carry on the treatment or do a water change and treat with something else?

 

[shang hi]

do the full length of treatment just to be sure. i would keep an eye on the two barbs with holes in their dorsal fins but im no more help than that so sorry...