I have changed both elements in my electric hotwater heater and adjusted the temp. it worked fine for about 3 days and then flipped the breaker again. Does anyone know what else to look for?

Something is shorting out the breaker. Seeing its electric, you may have to make sure no one is using a high powered thing on that breaker (aka hair dryer, dish washer, vacuum, etc.) you may need to designate that one breaker strictly to the water heater.