So I had 10 nice lil CBS mischlings for about a month, and had a little kit with some Cholla wood and other stuff. I had previously used some of the Cholla wood, but I guess one piece was bad because after I put it in everything, even the pest snails, was dead two hours later ... except two shrimp. I quickly removed them to a different container and did a 50% water change. One lived for a few more days, but later passed. Here's the tricky part: the one survivor molted two days after being placed in the container, and seemed very brown afterwards. Now, her black markings have turned entirely red. I am very concerned since the black markings turn red when they die, especially because I have since moved her into my main shrimp tank. Is this some sort of toxin?? What on Earth is happening?