hello,we have a 30 gal. with 10 painted glass tetras.on the fins of 4 tetras there are what i thought was ick.i have been treating the tank for 7 days and no change.could it be somthing else?it looks likewhite specks on the outer parts of the fins.the instructions said 1 drop per gal.and for tetras 1 drop per 2 gal.so i only add 15 drops.also when then are ick free can they be added to a tank with mollies?thanks