My silver Aro has been acting weird lately. his tail area seems to be rather lifeless.its more like hanging down but its not prominent. and he goes to the bottom n chill smtimes n then starts swim again! sm times he tries to jump out,but not in a very aggressive manner.Other than that,he seems to be fine.No extream agitations.However,i consulted my LFS,and i was toldit should be sm bacteria infection,and i got some medication for the fish. I followed up the instructions and also removed the sandy bottom of my tank,as a precaution(so no worms or other harmful things would hv no chance to hide).Removed 50% of water,and i added salt as well. Everything i mentioned took place yesterday.I hoped to see some improvement of the fish,but i see nothing. what do you think i should do? thanks in advance!