Possible copper poisoning
I had a mishap today/last night. My battery powered thermometer fell into the tank and corroded over night. It looks like the nastiest stuff stayed inside, but there was a brown residue (copper I fear) on the outside of the thermometer which I found floating in the tank.
Am I doomed? Nothing shows any signs of distress yet. I did a water change, and am about to go get some Cuprisorb. Will this help? Is it all over? I cant believe this has happened! I must have knocked it in somehow and had no idea.