In the last 10 days I have found at least 15 dead rcs. They didn't all die at once. Just one or two a day. If it was a copper or other poison world they have all died at once or slowly like mine did. Did spray a little bug spray in another room so maybe some got in. But only deaths i in that tank are the shrimp. All the fish are great including some juveniles. No shrimp deaths in another tank. Anything to do besides extra water changes?