Almost all my fish are dead

[rookie954]

:help: :help: :help: :help: :help:

I have had my 55 gal for close to 4 months now. I let the entire thing cycle for two monts with
live rocks
6 Damsels
5 red legged hermits
10 turbo snails.
I then proceeded to remove the damsels and added a royal grama. Two weeks later I added
1 Half black angel
1 Yellow Tang
1 Percula.
1 Cleaner wrass
All four fish were doing fine, I waited two more weeks and added a coral Beauty. All my fish were fine until 2 1/5 weeks ago all died except the Yellow tang and the Percula. I had my water tested and all was fine, So i purchased a flame angle and a Jap Wrass and they also died leaving again the Tang and the Percula. I took the water again to the LFS and it tested fine. I purchased another cleaner Wrass aon Saturday and today Monday he also died. I am back to just the Yellow tang, the percula left and the crabs and snails.
I need some advice please. I don't know what to do
My LFS is telling me my water is fine, if so what is killing my fish?

 

[elvictre]

How are you acclimating these fish? It could be that you are not acclimating them properly.

 

[fulofcharm]

you should wait a month for each new fish!! also when you put your new fish in your tank?? you should turn off the light for 24 hours so they can get comfortable!! good luck!:joy: