So I have recently had 3 fish die randomly (no ich, velvet, etc). Two were Flasher Wrasse's (one Blue Flasher, one McCoskers Flasher), and one was a Copperband Butterfly. They all came from the same LFS. They lasted about 2 weeks, and were doing really great before their sudden deaths.
In both cases, after about 2 weeks, they stopped eating one night during feeding (after eating well the whole time) and by the next morning are on the sandbed dead and I can't explain it.
No other fish in my tank have any issues (2 DaVinci Clowns, 2 Bangaii Cardinals, 1 Yellow Watchman Goby).
I've read on various forums that it could be the collection method. Some vendors use cyanide and that can cause random sudden death of fish a few weeks after they are collected, anybody know if any of the local shops here purchase from vendors using this method? I know its unlikely, but just trying to cover any possible issue it could be.
I have no clue otherwise, anyone with another idea?
Current tank Parameters:
Nitrate : 5 Phosphate: 0.19 (this is higher than I'd like)
Alkalinity: 8.8 dKH
I appreciate any advice