Sick Fish (Another Newbie)

[macman]

Help! I've just lost 4 ocellaris clowns and a green chromis!

I've got a 55 gallon FOWLR - about 25 pounds live rock (well established when I bought it) and another 24 pounds of reef rock - the tank is about 3 months old and had cycled nicely - ammonia and nitrites at 0 and nitrates negligble, SG at 1.023.

I had the four clowns in, and they were doing really well, and then I added the chromis. Within about 2 weeks a couple of the clowns stated looking "dusty" - not really spotted, just sort of a dullishness to their color. Their eyes looked clear, and they were feeding well (I had to make sure that the chromis weren't getting all the food; as long as I was careful, everybody got fed.)

Then a few days ago one of the clowns died. Two days later, yesterday, and two more of the clowns were gone. The last one was looking really mottled - white splotches all over. He had also stopped eating. I quarintined him in a small container hoping to take him to my LFS today (it was too late last night), but by the end of the evening he was gone.

Now my wife just called and one of my chromis is dead!

I don't know enough to say if this is ich or something else, and I can't get to my LFS until tomorrow. I'm open to any suggestions before I loose any more fish...

Help!