Fish Dying

[seanb]

Please help 100g tank
Every time I add a fish it seems to eat fine for 2 days, then on the third day, the fish is breathing heavy and then dies
Added
Diamond Goby
Greenbird Wrasse
Yellow Tang
Naso Tang,
All other fish in the tank doing fine no symptoms eating week, soaking food in garlic, noticed yellow tang dead, no visible signs except color kind of brown
100 G Aquarium built in filter in back
2 heaters
Skimmer
15 W UV Sterlizer
Rio Power Head 1700 and 800
Any help would be appreciated
Ammonia 0
Nitrite 0
Ph 8.3 to 8.4
Salinity 1.017
Temp 80

 

[seanb]

Salinity is low, because the I have read that for fish only you can keep at 1.017, for accimilation floated bag for 30 minutes, then added some my water, then dumped water then released fish in tank
Current fish in tank
Maroon clown pair
Six Line Wrasse
Goby
Bluen Tang
Foxface
Flamehawk
the problem is new fish are not living more than 3 days that I add to the tank, they are fine until the 3rd day, I saw some blotches on my naso tang this morning

 

[seanb]

Nitrates are at about 10, no real aggression from blue tang, basically any fish I add to the tank dies in 3 days, eats for 2 well, then dies on 3rd day, I am puzzled don't know what to do
Accimilation is as follows
I float the bag for about 20 minutes, then add water from my tank every 10 minutes for about 30 minutes, then dump fish in tank

 

[hip68]

Your not dumping the water that the fish came home in into your tank are you? Ive been told that is a definite no-no due to conditions beyond your control at the LFS. Could they possibly be sending you ich in the water and you are dumping it into your tank?