think my puffer has fungus!!!

[luv4reef]

Ok I need some advice, I have a porc. puffer (been in the tank for 3 wks) I just added 3 smaller fish the other day, none of which bother him but yesterday I noticed a discoloration on his upper lip and a little on his lower lip at first I thought the new small huma trigger nipped him but as I look at it more it looks like some kind of fungus growth...yikes! I am new to this and I need advice on the best way to treat it.
(i do not have a quarantine tank)
Does anyone have info on the diff. kinds of illnesses puffers are prone too? Thank you!!
:help:

 

[luv4reef]

sorry, I couldn't get a clear picture but this is what it looks like.

 

[luv4reef]

Also, my water tested good in all areas.
We did a very small water change yesterday too (1st water change)
The puffer is eating but as always only if it is live, we never could get him to take the frozen, oh well. He seems to be acting/breathing normal he just has this stuff. suggestions on meds?