Well I have to take issue with the conclusion that the problem is the evil LFS. Let see, here are the facts as I read them:

1.) Tank has been set up roughly 8 weeks.
2.) Fish additions in that time are:
1 - yellowtail damsel
unspecified # of other damsels
1 - bicolor angel
1 - coral beauty
1 - maroon clown
1 - unspecified goby
1 - yellow tang
For a total of at least 8 fish

3.) Tank parameters (ammonia, nitrite, etc.) are unknown.

Conclusion - It's the LFS's fault. HUH?

Also, it is erroneous to suggest that there is ANY source for fish that will absolutely guarantee that you will not introduce any type of parasite or disease to your system. Show me an LFS or online supplier who will not only give you your money back if the fish develops a disease but will also replace any other fish you might lose because of it and I will gladly retract this statement.
Please follow the advice of ISIS and any decent beginners saltwater book and setup an inexpensive quarantine tank. It will surely save you money and headaches.

I'm not trying to defend all LFS's - there are those who simply do not care. But let's be fair here.

Richard
CB Pets