Shrimp Help

[Murminator]

Why do shrimp hate me?? Quite a few months back I bought a sexy shrimp looked happy healthy appeared to be eating then one week to the day he died so I chalked it up to inexperience and a fairly new reef 2 months old. I did do the tests everything was perfect. Now last week I thought I would try another shrimp this time a cleaner everything seem fine he was active he liked to be hand fed through a syringe, he would reach up inside a pull food out. Then exactly 1 week to the day dead he was swaying around in the morning before work when I came home he was lying dead underneath a rock ledge. Once again I tested everything and it was perfect. I fed them Cyclopeeze, Marine Cuisine, Emerald Entree, Marine Max, flake and whatever else I have.
What am I doing wrong?? Any ideas??

I have noticed time to time that my nitrate has moved a little off 0 but not enough to register the next number. I just think it is the lighting putting the color off a bit.