Sparkling Diamonds

Actually, pennies were all copper before 1968. So, any pennies after that year all jsut have the copper plating on them, whereas the pennies that are dated 1968 or before, are actually all copper.

Phloxface

A copper penny in the tank would kill them. My boss told me his son had a fish tank and threw a penny into it and all the fish died within hours.

griffin

i'm far more likely to believe that there was something on the penny that caused the deaths. i know of people who were trying to kill off things like snails and shrimp (which are more sensitive than fish) put pennies in their tanks with no ill effects.

do i recommend putting random stuff like pennies in your tank? no. but do i think a clean penny will do much? not really.

Sparkling Diamonds

It could also have been that your boss' son put in a penny from 1968 or earlier, which would be a higher concentrate of copper, anything after that if washed properly should be absolutely fine since it's only a copper plating on the penny and not an actual copper penny.

griffin

agreed