Check your water. Cons are like rabbits that breed like crazy. Are they together? Other fish bothering them will make them less likely to breed. Although I use to have a pair that bred every month in a 220 with 2 12in red devils lol.
Tank isn't grounded, so it doesn't complete circuit. It doesn't shock when you have on shoes, but shocks when u dont, I've experienced it on my saltwater tank years ago. lol