Anyone else have certain Zoo's they can't keep???

[Kaos]

My tank is full of zoo's that are spreading pretty good. But some Zoo's just don't do well in my tank. I don't know if it's flow, lighting, chemical, etc. It really stinks because PPE's don't seem to do well and that's my favorite Zoo.

It all starts the same. I'll get a shipment of Zoo's. They'll open, reluctantly, over a few days and then seem to do ok after that. A month or two later they will start opening only partially or closing up often while the lights are on. Then, they just stop opening all together and waste away. I have had this happen to PPE's, Yellow Eclipses, and Nazanines. The confusing thing is the multiple other types of Zoo's I have do great. I've tried moving the unhappy Zoo colonies to more/less light and more/less flow area's, but it never helps (long term). My param's are right were they should be and the tank has SPS and LPS corals that are doing fine also.

So does anyone else have a problem w/ keeping certain types of Zoo's, or is this just me?