We are only getting about 10 minutes of water from our hot water heater recently. Today I replaced both elements, thinking one was bad and it made no difference. What else could be causing this?

GE ELECTRIC WATER HEATER Model # GE50M6A

How hot water heaters work, common problems with water heaters, and how to repair, fix, and maintain water heaters complete with diagrams

Good info here, this should help. Good luck

One of your thermostats may be bad, consequently only one element is heating. Thermostats are easy to replace and not expensive. It's worth a try. When I replace heating elements I always replace the thermostats too... just to be sure.