I am new to the vaping world. A friend of mine introduced me to it and I decided it was time to quit smoking analogs. I have a 2 year old with asthma so I figured I would be doing both of us a favor. I am currently sporting an ego-c upgrade battery with an iclear 16 dual core. I havent tried many juices yet. I like the fruity ones but I cant handle a strong throat hit. It irratates my throat. I like Halo midnight apple and Liqua berry mix. Any suggestions on juices to try? How can you tell when you need to replace a core?