Its never good to have ill fish, the great thing about tropical tanks however is that you can treat it fairly sucessfully with copper based medications, in a marine tank this is far more difficult.
I have tested with all kinds of "supposed" cures when one of my tangs (in marine) came down with the marine varient. I can tell you that no increase in temprature or anything else will help. The way I finally treated this was with UV filters and quarantine (as I could not treat the whole tank), I know that your tank is not marine but ich shows similar symptoms in both marine and tropical tanks.
I used to keep trops for about 8 years and found that some myxazin general tonic was great at fighting the bacteria and helped to reduce the fishes iritation, if you dont like copper based treatments and would prefer a natural method, a uv filter on an external filter outlet will nuke pretty much all bacteria (good and bad) and does a great job at killing the ICH parasite in its free swimming stage of its lifecycle, this is great to prevent further infection as well as keep nasty algea at bay.
Hope the little fella is ok.
