First 3 fish - dead

I have had my tank up and running for almost 5 weeks now. 55 Gal. 65 Pnds of Live rock. I have a CUC in there doing a great job and I also have 2 cleaner shrimp and 3 peppermint shrimp that are doing fine. They have been in there 2 weeks and the peppermint shrimp did a great job removing the aiptasia.

I purchased 3 green Chromiis from my LFS yesterday and this morning they were dead... I am extremely confused at what caused this??

PH 8.0 (i know that needs to be slightly higher)
Ammonia 0
Nitrite 0
Nitrate 10
Calcium 400
Phosphate 0 -.25 (hard to tell by the color strip)
KH - 10
Salinity is fine too i am just drawing a blank on th exact # it was.

Am I overlooking anything? Everything cycled so I am not sure why they died... and why so quickly? I know my cleaner shrimp were excited when I put the Chromis in the tank. Its not possible they harrassed them to the point of death is it? They left them alone after the first 20 minutes or so when i was watching. I unfortunately had to leave for work after that. Come back home and they were dead in the monring. 3rd shifter here

Any Advice would be great. I am currently thinking of not adding anything to the tank until september now. Fairly busy this month.

 

How did you test the salinity? How did you acclimate the fish?

 

I test that with a basic Hydrometer. I let the bag with the fish sit in the aquarium for about 15 minutes to adjust temp wise and opened the bag and placed it into a clean bucket and did the drip process for about 30 minutes.

 

my guess is the acclimation. were they floating? or were they kinda torn up? also what is the temp of the tank?

 

The fish when I found them? They were on the bottom, one of my peppermint shrimp appeared to be enjoying one of them. Temp is at 78.

Is there anything else I should be testing that could be so far off it caused them to die so quickly? I feel like if my water was really bad That my shrimp wouldnt still be doing fine.

 

There is nothing that I can really think of to test for... It sounds as if you have a pest in your tank, or the shrimp took em down. I can't imagine theyd do that so fast though. Could you post a picture of your setup?

 

I think they could have either faught to the death or they were on the way out when you bought them. The params seem good and i acclimate my fish the same way. I might have been one of those things. I have noticed that since I have switched tanks I cant keep occy clowns no matter what I do, but I can keep a coral beauty which is more sensitive. I think you should put in even numbers of fish too.

 

Yea I am just not sure. I am just going to let my tank sit now until september. I'll just wait and see if my shrimp continue to survive. They certainly seem completely fine. Very active.

Has anyone ever heard of cleaner shrimp or peppermint shrimp killing fish? Besides that I just dont know what it was. Unless the fish were in poor shape when I bought them, like was stated. They seemed fine at the store tho

 

Those hydrometers are not accurite, get a refractometer and calibration solution, $30 from brs. I think salinity might be it. What kind of filtration do you have?

 

Chromis? I always thought odd, with females in the majority