sick clown fish?
 

So I have 2 Black Clowns (tank bred) picked them up from Big Als about a week ago now and today I noticed on both of them the first fin on the top is becoming almost clearish in colour.

They are still eatting and swimming around just fine, nip each other a bit but not very often the QT tank is 20gal and they have lots of space to roam, theres also a bunch of LR rubble in the bottom of the tank just so its not bare.

Any idea what could be wrong with them?

Edit: pictures
(Large files sorry)
http://img301.imageshack.us/img301/5973/img7160l.jpg
http://img253.imageshack.us/img253/9428/img7161m.jpg

anyone got an idea? I have been looking but found nothing on what it could be.

Ammonia-0ppm
Nirites-0ppm
Nirates-less than 5ppm
PH-8.0-8.2
SG 1.025
Temp 79


heres a picture showing what I mean
http://img258.imageshack.us/img258/6058/img7161.png

It could be a bit of fin rot,from a bacterial infection,you could use something like melafix for bacterial infections,it's worked great for me in the past,if your water parameters are good in your QT it could go away on it's own.