Can Ghost Shrimp kill Corys?
I have a 46g bowfront with a bunch of livebearers and (until 2 days ago) 3 cory cats. The water is 33% changed weekly, and has 0 ammonia and nitrite, and 20ppm nitrate. The corys have been fine for months. I purchased a few ghost shrimp to try to help out with some cleaning of the tank (e.g. hair algae) and 5 cardinal tetras to try to brighten up the bottom 1/3rd of the tank. The cardinals all died within a few days - I have high pH, and that probably did it. 48 hours later, overnight, all three corys died. There are no signs of any distress from any of the mollies or guppies or the lonely painted glass tetra in the tank.
Is it possible that somehow the ghost shrimp killed the corys??