How do you say you are not into her anymore?

I joined this Filipina bride tours a while back and dated a Filipina I met during the tour. We actually dated for a while. She was fun to talk to although she was a bit struggling with her English. I was really into her at that time but I eventually lost interest. We struggle with our communication and our time zones are on opposite ends; a 13-hour difference. Now, I'm struggle on how can I tell her that I am not interested on dating her anymore. How can I tell her this?